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Journal articles on the topic 'Cyclopropane Ring'

Author: Grafiati

Published: 4 June 2021

Last updated: 6 September 2023

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1

Craig, Alexander J., and Bill C. Hawkins. "The Bonding and Reactivity of α-Carbonyl Cyclopropanes." Synthesis 52, no. 01 (October 1, 2019): 27–39. http://dx.doi.org/10.1055/s-0039-1690695.

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The cyclopropane functionality has been exploited in a myriad of settings that range from total synthesis and methodological chemistry, to medical and materials science. While it has been seen in such a breadth of settings, the typical view of the cyclopropane moiety is that its reactivity is derived primarily from the release of ring strain. While this simplified view is a useful shorthand, it ignores the specific nature of cyclopropyl molecular orbitals. This review aims to present the different facets of cyclopropane bonding by examining the main models that have been used to explain the reactivity of the functionality over the years. However, even with advanced theory, being able to precisely predict the reactivity of an exact system is nigh impossible. Specifically chosen, carbonyl-bearing cyclopropyl species act as so-called acceptor cyclopropanes and, if correctly derivatised, donor–acceptor cyclopropanes. By undertaking a case study of the history of carbonyl cyclopropanes in organic synthesis, this review highlights the relationship between the understanding of theory and pattern recognition in developing new synthetic methods and showcases those successful in balancing this critical junction.1 Cyclopropanes2 The Strain Model3 The Forster–Coulsin–Moffit Model4 The Walsh Model5 Acceptor, Donor, and Donor–Acceptor Cyclopropanes6 Reactions of Carbonyl Cyclopropanes

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2

Kohout, Ladislav. "The synthesis of 5,6-cyclopropanocholestanes with oxygen functions in positions 3 and 7." Collection of Czechoslovak Chemical Communications 51, no. 2 (1986): 429–35. http://dx.doi.org/10.1135/cccc19860429.

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The Simmons-Smith methylenation of the double bond in 3β-acetoxycholest-5-en-7-ols takes place selectively under formation of an adduct the configuration of which is determined by the configuration of the 7-hydroxyl group: 7β-alcohol IV gave 5β,6β-cyclopropane derivative VI, 7α-alcohol V gave 5α,6α-cyclopropane derivative VIII. On photochemically initiated cyclization of 3β-acetoxy-B-homo-5-en-7a-one (XIII) we obtained the product with an α-cyclopropane ring exclusively, i.e. 3β-acetoxy-5,6α-cyclopropano-5α-cholestan-7-one (XII).

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3

Singh, Satya Prakash, and Pompozhi Protasis Thankachan. "Hydroboration of Substituted Cyclopropane: A Density Functional Theory Study." Advances in Chemistry 2014 (August 18, 2014): 1–7. http://dx.doi.org/10.1155/2014/427396.

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The hydroboration of substituted cyclopropanes has been investigated using the B3LYP density functional method employing 6-31G** basis set. Borane moiety approaching the cyclopropane ring has been reported. It is shown that the reaction proceeds via a three-centered, “loose” and “tight,” transition states when boron added to the cyclopropane across a bond to a substituents. Single point calculations at higher levels of theory were also performed at the geometries optimized at the B3LYP level, but only slight changes in the barriers were observed. Structural parameters for the transition state are also reported.

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4

Trudeau, Stéphane, and Pierre Deslongchamps. "Novel synthesis of a highly functionalized cyclopropane derivative." Canadian Journal of Chemistry 81, no. 9 (September 1, 2003): 1003–11. http://dx.doi.org/10.1139/v03-119.

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A model study was carried out to explore the feasibility of synthesizing fused tricyclic ring structures containing a C7C8 double bond juncture (steroid numbering) by employing an SN2' cyclization of a silyl enol ether to displace an allylic acetate as the key step. Instead of the anticipated product, highly functionalized cyclopropanes were obtained. These novel cyclopropane structures are the result of the concomitant 1,2-migration of a dithiane thioether moiety and the eventual displacement of the acetate group, followed by the cyclization of the silyl enol ether.Key words: tricycles, SN2' cyclization, inductive effect, cyclopropane.

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5

Babu, Kaki Raveendra, Xin He, and Silong Xu. "Lewis Base Catalysis Based on Homoconjugate Addition: Rearrangement of Electron-Deficient Cyclopropanes and Their Derivatives." Synlett 31, no. 02 (November 20, 2019): 117–24. http://dx.doi.org/10.1055/s-0039-1690753.

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Cyclopropane is one of the most reactive functionalities owing to its intrinsic ring strain. Transition-metal catalysis and Lewis acid catalysis have been extensively used in ring openings of cyclopropanes; however, Lewis base-catalyzed activation of cyclopropanes remains largely unexplored. Upon nucleophilic attack with Lewis bases, cyclopropanes undergo ring cleavage in a manner known as homoconjugate addition to form zwitterionic intermediates, which have significant potential for reaction development but have garnered little attention. Here, we present a brief overview of this area, with an emphasis on our recent efforts on Lewis base-catalyzed rearrangement reactions of electron-deficient cyclopropanes using the homoconjugate addition process.1 Introduction2 DABCO-Catalyzed Cloke–Wilson Rearrangement of Cyclopropyl Ketones3 Hydroxylamine-Mediated Tandem Cloke–Wilson/Boulton–Katritzky Reaction of Cyclopropyl Ketones4 Phosphine-Catalyzed Rearrangement of Vinylcyclopropyl Ketones To Form Cycloheptenones5 Phosphine-Catalyzed Rearrangement of Alkylidenecyclopropyl Ketones To Form Polysubstituted Furans and Dienones6 Conclusion and Outlook

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6

Budynina, Ekaterina, Konstantin Ivanov, Ivan Sorokin, and Mikhail Melnikov. "Ring Opening of Donor–Acceptor Cyclopropanes with N-Nucleophiles." Synthesis 49, no. 14 (May 18, 2017): 3035–68. http://dx.doi.org/10.1055/s-0036-1589021.

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Ring opening of donor–acceptor cyclopropanes with various N-nucleophiles provides a simple approach to 1,3-functionalized compounds that are useful building blocks in organic synthesis, especially in assembling various N-heterocycles, including natural products. In this review, ring-opening reactions of donor–acceptor cyclopropanes with amines, amides, hydrazines, N-heterocycles, nitriles, and the azide ion are summarized.1 Introduction2 Ring Opening with Amines3 Ring Opening with Amines Accompanied by Secondary Processes Involving the N-Center3.1 Reactions of Cyclopropane-1,1-diesters with Primary and Secondary Amines3.1.1 Synthesis of γ-Lactams3.1.2 Synthesis of Pyrroloisoxazolidines and -pyrazolidines3.1.3 Synthesis of Piperidines3.1.4 Synthesis of Azetidine and Quinoline Derivatives3.2 Reactions of Ketocyclopropanes with Primary Amines: Synthesis of Pyrrole Derivatives3.3 Reactions of Сyclopropane-1,1-dicarbonitriles with Primary Amines: Synthesis of Pyrrole Derivatives4 Ring Opening with Tertiary Aliphatic Amines5 Ring Opening with Amides6 Ring Opening with Hydrazines7 Ring Opening with N-Heteroaromatic Compounds7.1 Ring Opening with Pyridines7.2 Ring Opening with Indoles7.3 Ring Opening with Di- and Triazoles7.4 Ring Opening with Pyrimidines8 Ring Opening with Nitriles (Ritter Reaction)9 Ring Opening with the Azide Ion10 Summary

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7

Liu, Yu, Qiao-Lin Wang, Zan Chen, Cong-Shan Zhou, Bi-Quan Xiong, Pan-Liang Zhang, Chang-An Yang, and Quan Zhou. "Oxidative radical ring-opening/cyclization of cyclopropane derivatives." Beilstein Journal of Organic Chemistry 15 (January 28, 2019): 256–78. http://dx.doi.org/10.3762/bjoc.15.23.

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The ring-opening/cyclization of cyclopropane derivatives has drawn great attention in the past several decades. In this review, recent efforts in the development of oxidative radical ring-opening/cyclization of cyclopropane derivatives, including methylenecyclopropanes, cyclopropyl olefins and cyclopropanols, are described. We hope this review will be of sufficient interest for the scientific community to further advance the application of oxidative radical strategies in the ring-opening/cyclization of cyclopropane derivatives.

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8

Matyas, Libor, Radek Pohl, and Alexander Kasal. "Neighboring Group Participation in 12,20-Dioxopregnanes." Natural Product Communications 2, no. 11 (November 2007): 1934578X0700201. http://dx.doi.org/10.1177/1934578x0700201108.

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12,20-Dioxo-5α-pregnan-3β-yl acetate, obtained from hecogenin, was treated with NaH in DMSO to yield the bridged cyclopropano ketone, 3β-hydroxy-12α,21-cyclo-12β,21-methano-5α,17α-pregnan-20-one. In tert-BuOH the reaction leads to 3β-hydroxy-12,21-cyclo-5α-pregn-12,21-en-20-one. Experimental data prove that the new methylene group of the cyclopropane ring came from DMSO.

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9

Song, Xixi, Junbiao Chang, Yuanyuan Zhu, Shuang Zhao, and Minli Zhang. "Diastereoselective Synthesis of Spirobarbiturate-Cyclopropanes through Organobase-Mediated Spirocyclopropanation of Barbiturate-Based Olefins with Benzyl Chlorides." Synthesis 51, no. 04 (November 6, 2018): 899–906. http://dx.doi.org/10.1055/s-0037-1609637.

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The organobase-mediated diastereoselective spirocyclopropanation of barbiturate-based olefins with 2,4-disubstituted benzyl chlorides has been developed. The reactions were carried out efficiently to afford the desired spirobarbiturate-cyclopropanes in up to 95% yield with more than 20:1 dr in favor of anti-isomers. In order to extend synthetic utility of the spiro-products, a Lewis acid induced cyclopropane-ring-expansion isomerization was also demonstrated.

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10

Miranda, Margarida S., Darío J. R. Duarte, Joaquim C. G. Esteves da Silva, and Joel F. Liebman. "Protonated heterocyclic derivatives of cyclopropane and cyclopropanone: classical species, alternate sites, and ring fragmentation." Canadian Journal of Chemistry 93, no. 7 (July 2015): 708–14. http://dx.doi.org/10.1139/cjc-2015-0029.

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A computational study has been performed for protonated oxygen- or nitrogen-containing heterocyclic derivatives of cyclopropane and cyclopropanone. We have searched for the most stable conformations of the protonated species using density functional theory with the B3LYP functional and the 6-31G(2df,p) basis set. More accurate enthalpy values were obtained from G4 calculations. Proton affinities and gas-phase basicities were accordingly derived.

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11

Ivanova, Olga, Vladimir Andronov, Irina Levina, Alexey Chagarovskiy, Leonid Voskressensky, and Igor Trushkov. "Convenient Synthesis of Functionalized Cyclopropa[c]coumarin-1a-carboxylates." Molecules 24, no. 1 (December 24, 2018): 57. http://dx.doi.org/10.3390/molecules24010057.

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A simple method has been developed for the synthesis of cyclopropa[c]coumarins, which belong to the donor-acceptor cyclopropane family and, therefore, are promising substrates for the preparation of chromene-based fine chemicals. The method, based on the acetic acid-induced intramolecular transesterification of 2-arylcyclopropane-1,1-dicarboxylates, was found to be efficient for substrates containing hydroxy group directly attached to the aromatic ring.

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12

Vereshchagin, Anatolii N., Michail N. Elinson, Nikita O. Stepanov, and Gennady I. Nikishin. "New Way to Substitute Tetracyanocyclopropanes: One-Pot Cascade Assembling of Carbonyls and Malononitrile by the Only Bromine Direct Action." ISRN Organic Chemistry 2011 (July 26, 2011): 1–5. http://dx.doi.org/10.5402/2011/469453.

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The new type of the chemical cascade reaction was found: formation of cyclopropanes from carbonyl compounds and CH acid by the only bromine direct action. The action of aqueous bromine on the carbonyl compounds and malononitrile in EtOH-H2O solutions in the presence of NaOAc results in the formation of 3-substituted 1,1,2,2-tetracyanocyclopropanes in 48–93% yields. The latter are well-known precursors for the different bicyclic heterosystems, among them those containing cyclopropane ring and those possessing different types of pharmacological activity.

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13

Fowler, Patrick W., Jon Baker, and Mark Lillington. "The ring current in cyclopropane." Theoretical Chemistry Accounts 118, no. 1 (February 10, 2007): 123–27. http://dx.doi.org/10.1007/s00214-007-0253-2.

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14

BURRITT, A., CORON J. M. CORON J. M., and P. J. STEEL. "ChemInform Abstract: Cyclopropane Ring Opening." ChemInform 27, no. 44 (August 4, 2010): no. http://dx.doi.org/10.1002/chin.199644271.

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15

Kieboom, A. P. G., A. J. Breijer, and H. van Bekkum. "Stereochemistry of cyclopropane ring hydrogenolysis." Recueil des Travaux Chimiques des Pays-Bas 93, no. 7 (September 2, 2010): 186–89. http://dx.doi.org/10.1002/recl.19740930704.

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16

Corfield, Peter W. R., and Richard A. Kershaw. "Crystal structures of two bicyclo[5.1.0]octanes: potassiumtrans-bicyclo[5.1.0]octane-4-carboxylate monohydrate andcis-bicyclo[5.1.0]octan-4-yl 4-bromobenzenesulfonate." Acta Crystallographica Section E Crystallographic Communications 73, no. 9 (August 21, 2017): 1357–62. http://dx.doi.org/10.1107/s2056989017011756.

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The crystal structures of thetrans-fused compound potassiumtrans-bicyclo[5.1.0]octane-4-carboxylate monohydrate, K+·C9H13O2−·H2O, (I), and ofcis-bicyclo[5.1.0]octan-4-yl 4-bromobenzenesulfonate, C14H17BrO3S, (II), have been determined. Compound (I) represents the smallesttrans-fused cyclopropane structure known to date, and features the expectedshorteningof the bridging C—C bond relative to the other cyclopropane bond lengths, in contrast to thecis-fused system, (II), where all of the cyclopropane bond lengths are the same. The bicyclic ring system of (I) is disordered across a crystallographic mirror plane. The geometries of thecis-fused andtrans-fused ring systems are compared.

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17

Ha, Hyun-Joon. "Preface to “Aziridine Chemistry”." Molecules 26, no. 6 (March 11, 2021): 1525. http://dx.doi.org/10.3390/molecules26061525.

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18

Sedenkova, Kseniya N., Kristian S. Andriasov, Tamara S. Kuznetsova, and Elena B. Averina. "Oxyfunctionalization of CH2-Group Activated by Adjacent Three-Membered Ring." Current Organic Synthesis 15, no. 4 (June 12, 2018): 515–32. http://dx.doi.org/10.2174/1570179415666180405113158.

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Background: Increasing use of the three-membered ring in drug development initiates the search for efficient methods of transformations of cyclopropane derivatives. Oxidation of methylene group activated by an adjacent cyclopropane represents a direct approach towards carbonylcyclopropanes, allows avoiding unnecessary synthetic stages and meets the requirements of atom economy. Objective: In this review all available data concerning the oxidation of cyclopropane-containing hydrocarbons and their functionally substituted derivatives are systematized, and the general regularities between the structure of the starting compound, the oxidant employed and the reaction outcome are underlined. Conclusion: The following regularities were distinguished for the oxidation of cyclopropane-containing compounds into cyclopropylketones. The main structural parameters of the starting compounds, which influence the distribution of the oxidation products, are the followings: the presence of competing C-H bonds, flexibility or rigidity of structure, electron and sterical substituents effects. A number of preparative methods of activated C(sp3)-H bonds oxygenation were elaborated, employing such powerful oxidants as ozone, dioxiranes, CrO3 and a variety of catalytic systems, based on transition metals. For the oxidation of cyclopropane derivatives all these oxidants may be employed. RuO4, generated in situ, usually behaves as selective and soft oxidant. TFDO often demonstrates lesser selectivity, but it may be the best choice when several activated CH2 groups should be oxidised. In the case of dihalocyclopropanes the use of CrO3 is preferable. Summarily, the oxidation of methylene group adjacent to cyclopropane has been undoubtedly developed into a reliable preparative approach to cyclopropylketones, which should find an active use in synthetic organic chemistry.

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19

Edwards, Oliver E., Dusan Dvornik, Ralph J. Kolt, and Barbara A. Blackwell. "Formation, reactions, and NMR spectra of 1,20-cycloatidanes." Canadian Journal of Chemistry 70, no. 5 (May 1, 1992): 1397–405. http://dx.doi.org/10.1139/v92-178.

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Imines derived from the alkaloid atisine gave N-acetyl 1,20-cycloatidane derivatives when heated with acetic anhydride. Vigorous alkaline hydrolysis cleaved the cyclopropane ring, regenerating the parent imine. The 1H and 13C NMR spectra of several 1,20-cyclo derivatives have been assigned and compared to those of the parent imines 2. All of the N-acetyl compounds showed doubling of the majority of the NMR resonances, due to amide rotamers. The effects of the cyclopropane ring current are noted.

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20

Sathishkannan, Gopal, V. John Tamilarasan, and Kannupal Srinivasan. "Nucleophilic ring-opening reactions of trans-2-aroyl-3-aryl-cyclopropane-1,1-dicarboxylates with hydrazines." Organic & Biomolecular Chemistry 15, no. 6 (2017): 1400–1406. http://dx.doi.org/10.1039/c6ob02552h.

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trans-2-Aroyl-3-aryl-cyclopropane-1,1-dicarboxylates gave dihydropyrazoles when treated with arylhydrazines in refluxing EtOH, whereas they afforded cyclopropane-fused pyridazinones upon treatment with hydrazines in refluxing AcOH.

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21

Wanapun, D., K. A. Van Gorp, N. J. Mosey, M. A. Kerr, and T. K. Woo. "The mechanism of 1,3-dipolar cycloaddition reactions of cyclopropanes and nitrones A theoretical study." Canadian Journal of Chemistry 83, no. 10 (October 1, 2005): 1752–67. http://dx.doi.org/10.1139/v05-182.

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The 1,3-dipolar cycloaddition reaction of cyclopropanes and nitrones to give tetrahydro-1,2-oxazine has been studied with density functional theory calculations at the B3LYP/6-31+G(d,p) level of theory. Realistic substituents were modelled including those at the 2-, 3-, 4-, and 6-positions of the final oxazine ring product. The strained σ bond of the cyclopropane was found to play the role of an alkene in a conventional [3+2] dipolar cycloaddition. Two distinct, but similar, reaction mechanisms were found an asymmetric concerted pathway and a stepwise zwitterionic pathway. The reaction barriers of the two pathways were nearly identical, differing by less than ~1 kcal/mol, no matter what the substituents were. The effect of a Lewis acid catalyst was examined and found to have a very large effect on the calculated barriers through coordination to the carbonyl oxygen atoms of the diester substituents on the cyclopropane. The reaction barrier was found to decrease by as much as ~19 kcal/mol when using a BF3 molecule as a model for the Lewis acid catalyst. Solvent effects and the nature of the regiospecificity of the reaction were also examined. Trends in the calculated barriers for the reaction were in good agreement with available trends in the reaction rates measured experimentally. Key words: 1,3-dipolar cycloaddition, cyclopropane, nitrone, tetrahydro-1,2-oxazines, ab initio quantum chemistry, mechanism.

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22

Stubbs, Connor J., and Andrew P. Dove. "Understanding structure–property relationships of main chain cyclopropane in linear polyesters." Polymer Chemistry 11, no. 39 (2020): 6251–58. http://dx.doi.org/10.1039/d0py01004a.

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Rigid ring structures have gained increasing interest in the polymer materials community as an effective means to manipulate bulk properties. Here, we investigate structure–property relationships of the smallest ring: cyclopropane.

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23

Shields, Samuel, Peter Buist, and Jeffrey Manthorpe. "Asymmetric and Regiospecific Synthesis of Isotopically Labelled Cyclopropane Fatty Acid (9R,10S)-Dihydrosterculic Acid: Overcoming Spontaneous Protonation During Lithium-Sulfoxide Exchange." SynOpen 02, no. 02 (April 2018): 0168–75. http://dx.doi.org/10.1055/s-0036-1591976.

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The total synthesis of isotopically labelled (9R,10S)-dihydrosterculic acid, a usual cyclopropane fatty acid with biologically relevant toxicity upon desaturation in vivo, is reported. A diastereoselective Corey–Chaykovsky reaction was employed to form the cyclopropane ring. Rapid quenching of a lithium-sulfoxide exchange was required to achieve the requisite high levels of deuterium incorporation.

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24

Sun, Na-Bo, Guo-Wu Rao, and Jian-Bo Chu. "1-{[3-(2-Chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropan-1-yl]carbonyl}-3-(methylsulfonyl)imidazolidin-2-one." Acta Crystallographica Section E Structure Reports Online 68, no. 6 (May 16, 2012): o1744. http://dx.doi.org/10.1107/s1600536812021216.

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In the title molecule, C13H16ClF3N2O4S, the imidazolidine ring is approximately planar, the largest deviation from this plane being 0.025 (3) Å. The cyclopropane ring forms a dihedral angle of 64.1 (2)° with the imidazolidine ring. In the crystal, C—H...O hydrogen bonds are observed.

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25

Cohen, Theodore. "The production of cyclopropanes from organosulfur compounds and a novel cyclopropane ring expansion." Pure and Applied Chemistry 68, no. 4 (January 1, 1996): 913–18. http://dx.doi.org/10.1351/pac199668040913.

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26

Hayakawa, Kosuke, Shin-ichi Matsuoka, and Masato Suzuki. "Ring-opening polymerization of donor–acceptor cyclopropanes catalyzed by Lewis acids." Polymer Chemistry 8, no. 25 (2017): 3841–47. http://dx.doi.org/10.1039/c7py00794a.

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27

Allen, F. H., J. P. M. Lommerse, V. J. Hoy, J. A. K. Howard, and G. R. Desiraju. "The hydrogen-bond C–H donor and π-acceptor characteristics of three-membered rings." Acta Crystallographica Section B Structural Science 52, no. 4 (August 1, 1996): 734–45. http://dx.doi.org/10.1107/s0108768196005319.

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Crystallographic results, retrieved from the Cambridge Structural Database, show that the C--H protons of cyclopropane, aziridine and oxirane form C—H...O (particularly C—H...O—C) hydrogen bonds. The frequency of formation and geometrical characteristics of these bonds indicate a bond-strength ordering: Csp 1—H...O > C(ring)—H...O ≃ Csp 2—H...O > Csp 3—H...O, which is in excellent agreement with the well known ethylenic properties of C(ring)—H and with residual δ+ charges calculated for these systems. There is some evidence to suggest that C=C—H in cyclopropene, known to be a highly acidic H, forms stronger hydrogen bonds than C—H in saturated three-membered rings. Crystallographic data have also been used to provide geometrical evidence for the formation of O,N—H...π(ring) bonding to three-membered rings, proposed on the basis of spectroscopic data [Joris, Schleyer & Gleiter (1968). J. Am. Chem. Soc. 90, 327–336]. The two modes of H...π(ring) binding suggested there, viz. `edge-on' approach of H to a ring C—C bond and `face-on' approach towards the ring centroid, are found to be dominant in crystallographic observations of this novel hydrogen bond.

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28

Liu, Dong-Qing, Ya-Qing Feng, Da-Wei Liu, and Sha-Sha Zhang. "3-[(E)-2-Chloro-3,3,3-trifluoroprop-1-enyl]-2,2-dimethyl-N-(3-pyridyl)cyclopropanecarboxamide acetone hemisolvate." Acta Crystallographica Section E Structure Reports Online 62, no. 5 (April 7, 2006): o1747—o1748. http://dx.doi.org/10.1107/s1600536806012062.

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In the title compound, C14H14ClF3N2O·0.5C3H6O, the pyridine ring makes a dihedral angle of 73.0 (3)° with the cyclopropane ring. The amide NH group and the pyridine N atom are linked by an intermolecular N—H...N hydrogen bond.

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29

Ho, Hien The, Véronique Montembault, Marion Rollet, Soioulata Aboudou, Kamel Mabrouk, Sagrario Pascual, Laurent Fontaine, Didier Gigmes, and Trang N. T. Phan. "Radical ring-opening polymerization of novel azlactone-functionalized vinyl cyclopropanes." Polymer Chemistry 11, no. 24 (2020): 4013–21. http://dx.doi.org/10.1039/d0py00493f.

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30

Bacsa, John, and John Briones. "Determination of the electron density in methyl (±)-(1S,2S,3R)-2-methyl-1,3-diphenylcyclopropanecarboxylate using refinements with X-ray scattering factors from wavefunction calculations of the whole molecule." Acta Crystallographica Section C Crystal Structure Communications 69, no. 8 (July 13, 2013): 910–14. http://dx.doi.org/10.1107/s0108270113017496.

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The molecule of the title compound, C18H18O2, is a substituted cyclopropane ring. The electron density in this molecule has been determined by refining single-crystal X-ray data using scattering factors derived from quantum mechanical calculations. Topological analysis of the electron densities in the three cyclopropane C—C bonds was carried out. The results show the effects of this substitution on these C—C bonds.

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31

Bisag, Giorgiana Denisa, Pietro Viola, Luca Bernardi, and Mariafrancesca Fochi. "Divergent Reactivity of D-A Cyclopropanes under PTC Conditions, Ring-Opening vs. Decyanation Reaction." Catalysts 13, no. 4 (April 16, 2023): 760. http://dx.doi.org/10.3390/catal13040760.

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The divergent reactivity of D-A cyclopropane, under PTC conditions, is herein reported. Thus, a ring-opening or a decyanation reaction can be achieved by reacting 2-arylcyclopropane-1,1-dicarbonitriles 1 with thioacetic acid in different reaction conditions. The use of solid Cs2CO3 leads unexpectedly to the synthesis of new D-A cyclopropane derivatives via a decyanation reaction, followed by diastereoselective acetylation, whereas the use of an aqueous solution of Cs2CO3 results in a typical ring-opening reaction with the formation of S-thiolate products. Therefore, the use of tailored reaction conditions allows one to obtain either cyclic or open-chain products in moderate to good yields.

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32

Martin, Rachel, Minkyu Kim, Austin Franklin, Yingxue Bian, Aravind Asthagiri, and Jason F. Weaver. "Adsorption and oxidation of propane and cyclopropane on IrO2(110)." Physical Chemistry Chemical Physics 20, no. 46 (2018): 29264–73. http://dx.doi.org/10.1039/c8cp06125d.

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33

Cavitt, Marchello A., Lien H. Phun, and Stefan France. "Intramolecular donor–acceptor cyclopropane ring-opening cyclizations." Chem. Soc. Rev. 43, no. 3 (2014): 804–18. http://dx.doi.org/10.1039/c3cs60238a.

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34

Montgomery, J., and L. Liu. "Synthesis of Cyclopentanes via Cyclopropane Ring Opening." Synfacts 2006, no. 7 (June 2006): 0706. http://dx.doi.org/10.1055/s-2006-941863.

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35

Wallbaum, Jan, Lennart K. B. Garve, Peter G. Jones, and Daniel B. Werz. "Ring-Opening 1,3-Halochalcogenation of Cyclopropane Dicarboxylates." Organic Letters 19, no. 1 (December 14, 2016): 98–101. http://dx.doi.org/10.1021/acs.orglett.6b03375.

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36

Luis-Barrera, Javier, Víctor Laina-Martín, Thomas Rigotti, Francesca Peccati, Xavier Solans-Monfort, Mariona Sodupe, Rubén Mas-Ballesté, Marta Liras, and José Alemán. "Visible-Light Photocatalytic Intramolecular Cyclopropane Ring Expansion." Angewandte Chemie 129, no. 27 (June 6, 2017): 7934–38. http://dx.doi.org/10.1002/ange.201703334.

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37

Maier, Günther, and Stefan Senger. "Ring Opening of Cyclopropane at 10 K." Angewandte Chemie International Edition in English 33, no. 5 (March 17, 1994): 558–59. http://dx.doi.org/10.1002/anie.199405581.

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38

Luis-Barrera, Javier, Víctor Laina-Martín, Thomas Rigotti, Francesca Peccati, Xavier Solans-Monfort, Mariona Sodupe, Rubén Mas-Ballesté, Marta Liras, and José Alemán. "Visible-Light Photocatalytic Intramolecular Cyclopropane Ring Expansion." Angewandte Chemie International Edition 56, no. 27 (June 6, 2017): 7826–30. http://dx.doi.org/10.1002/anie.201703334.

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39

Chen, Gen-Qiang, Wei Fang, Yin Wei, Xiang-Ying Tang, and Min Shi. "Divergent reaction pathways in gold-catalyzed cycloisomerization of 1,5-enynes containing a cyclopropane ring: dramatic ortho substituent and temperature effects." Chemical Science 7, no. 7 (2016): 4318–28. http://dx.doi.org/10.1039/c6sc00058d.

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Gold-catalyzed cycloisomerization of 1,5-enynes containing a cyclopropane ring provides access to cyclobutane-fused 1,4-cyclohexadiene, 1,3-cyclohexadiene, tricyclic cyclobutene and biscyclopropane derivatives.

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40

Wang, Mei-Yi, and Ya Zhang. "(E)-(2,4-Dichlorobenzylidene)amino cyclopropanecarboxylate." Acta Crystallographica Section E Structure Reports Online 68, no. 6 (May 2, 2012): o1594. http://dx.doi.org/10.1107/s1600536812018016.

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In the title compound C11H9Cl2NO2, the dihedral angle between the benzene and cyclopropane ring planes is 89.95 (13)°. The carbonyl–oxime grouping is almost coplanar with the benzene ring [dihedral angle = 4.08 (6)°]. In the crystal, molecules are linked by C—H...O interactions into [100] chains.

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41

Szántay, Csaba, Péter Keglevich, László Hazai, Zsófia Dubrovay, Zsuzsanna Sánta, Miklós Dékány, Csaba Szántay, and György Kalaus. "Bisindole Alkaloids Condensed with a Cyclopropane Ring, Part 2. Cyclopropano-vinorelbine and Its Derivatives." HETEROCYCLES 90, no. 1 (2015): 316. http://dx.doi.org/10.3987/com-14-s(k)20.

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42

Koga, Yuji, and Koichi Narasaka. "Rhodium Catalyzed Transformation of 4-Pentynyl Cyclopropanes to Bicyclo[4.3.0]nonenonesviaCleavage of Cyclopropane Ring." Chemistry Letters 28, no. 7 (July 1999): 705–6. http://dx.doi.org/10.1246/cl.1999.705.

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43

Pyne, Stephen G., Karl Schafer, Brian W. Skelton, and Allan H. White. "Asymmetric Synthesis of Protected 2-Substituted Cyclopropane Amino Acids." Australian Journal of Chemistry 51, no. 2 (1998): 127. http://dx.doi.org/10.1071/c97105.

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The cyclopropanation reactions of (1a) with ethyl and t-butyl (dimethylsulfuranylidene)acetate proceeded with good diastereoselectivity and resulted in the formation of three diastereoisomeric products. The major diastereoisomeric product ((2a) and (2b), respectively) could be isolated in pure form by simple recrystallization. The stereochemistry of the major cyclopropane product (2b) has been determined by single-crystal X-ray structural analysis. These cyclopropanation products were susceptible to ring opening of the cyclopropane ring upon reduction with sodium borohydride or acid hydrolysis. The reaction of (1b) with ethyl (dimethylsulfuranylidene)acetate gave a mixture of four diastereoisomeric cyclopropanation products. The reactions of (1a) and (1b) with the sulfur ylide derived from 3-methoxycarbonylallyldimethylsulfonium bromide were less successful in terms of product diastereoselectivities.

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44

Xiao, Jun-An, Peng-Ju Xia, Xing-Yu Zhang, Xiao-Qing Chen, Guang-Chuan Ou, and Hua Yang. "Amide-assisted intramolecular [3+2] annulation of cyclopropane ring-opening: a facile and diastereoselective access to the tricyclic core of (±)-scandine." Chemical Communications 52, no. 10 (2016): 2177–80. http://dx.doi.org/10.1039/c5cc07485a.

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45

Srinivasan, Thothadri, Govindaraj Senthilkumar, Haridoss Manikandan, Mannathusamy Gopalakrishanan, and Devadasan Velmurugan. "1-Cyclopropyl-2-(2-fluorophenyl)-5-(4-fluorophenyl)-3-phenylpentane-1,5-dione." Acta Crystallographica Section E Structure Reports Online 69, no. 2 (January 9, 2013): o215. http://dx.doi.org/10.1107/s1600536813000032.

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In the title compound, C26H22F2O2, the cyclopropane ring makes dihedral angles of 47.6 (2), 51.3 (2) and 63.9 (2)° with the 2-fluoro-substituted phenyl ring, the unsubstituted phenyl ring and the 4-fluoro-substituted phenyl ring, respectively. There is a short C—H...F contact in the molecule. In the crystal, weak C—H...F hydrogen bonds lead to chains of molecules extending along theb-axis direction.

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46

Levitskiy, Oleg A., Olga I. Aglamazova, Yuri K. Grishin, and Tatiana V. Magdesieva. "Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives." Beilstein Journal of Organic Chemistry 18 (September 8, 2022): 1166–76. http://dx.doi.org/10.3762/bjoc.18.121.

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The involvement of an α,α-cyclopropanated amino acid in the chiral Ni(II) coordination environment in the form of a Schiff base is considered as a route to electrochemical broadening of the donor–acceptor cyclopropane concept in combination with chirality induction in the targeted products. A tendency to the reductive ring-opening and the follow-up reaction paths of thus formed radical anions influenced by substituents in the cyclopropane ring are discussed. Optimization of the reaction conditions opens a route to the non-proteinogenic amino acid derivatives containing an α–β or β–γ double C=C bond in the side chain; the regioselectivity can be tuned by the addition of Lewis acids. One-pot combination of the reductive ring opening and subsequent addition of thiols allows obtaining the cysteine derivatives in practical yields and with high stereoselectivity at the removed β-stereocenter.

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47

Srinivasan, Thothadri, Govindaraj Senthilkumar, Haridoss Manikandan, Kaliaperumal Neelakandan, and Devadasan Velmurugan. "5-(4-Chlorophenyl)-1-cyclopropyl-2-(2-fluorophenyl)-3-phenylpentane-1,5-dione." Acta Crystallographica Section E Structure Reports Online 69, no. 2 (January 19, 2013): o252. http://dx.doi.org/10.1107/s1600536813001074.

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In the title compound, C26H22ClFO2, the cyclopropane ring makes dihedral angles of 45.7 (2), 49.0 (2) and 65.2 (2)° with the fluoro-substituted phenyl ring, the benzene ring and the chloro-substituted phenyl ring, respectively. The F and Cl atoms deviate by 0.0307 (11) and 0.0652 (6) Å, respectively, from the planes of the phenyl rings to which they are attached. In the crystal, molecules are linked by C—H...F hydrogen bonds, forming chains along thebaxis.

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48

Csuk, René, and Gunnar Göthe. "Synthesis of Spacered Cyclopropanoid Muramyldipeptide Analogues as Potential Immunostimulants." Zeitschrift für Naturforschung B 58, no. 12 (December 1, 2003): 1247–54. http://dx.doi.org/10.1515/znb-2003-1216.

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A novel class of cyclopropanoic muramyldipeptide analogues containing an additional methylene spacer between the cyclopropane ring and the lactyl residue has been prepared by a straightforward synthesis starting from isopropyl (R)-lactate.

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49

Shi, Yinfeng, Holger Schmalz, and Seema Agarwal. "Designed enzymatically degradable amphiphilic conetworks by radical ring-opening polymerization." Polymer Chemistry 6, no. 35 (2015): 6409–15. http://dx.doi.org/10.1039/c5py00962f.

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A simple and versatile route for making functional biodegradable amphiphilic conetworks (APCNs) with unique swelling property and excellent enzymatic degradability is presented. The APCNs were made by radical ring-opening copolymerization of cyclic ketene acetal and vinyl cyclopropane derivative.

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50

Grogan, D. W., and J. E. Cronan. "Cyclopropane ring formation in membrane lipids of bacteria." Microbiology and Molecular Biology Reviews 61, no. 4 (December 1997): 429–41. http://dx.doi.org/10.1128/mmbr.61.4.429-441.1997.

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It has been known for several decades that cyclopropane fatty acids (CFAs) occur in the phospholipids of many species of bacteria. CFAs are formed by the addition of a methylene group, derived from the methyl group of S-adenosylmethionine, across the carbon-carbon double bond of unsaturated fatty acids (UFAs). The C1 transfer does not involve free fatty acids or intermediates of phospholipid biosynthesis but, rather, mature phospholipid molecules already incorporated into membrane bilayers. Furthermore, CFAs are typically produced at the onset of the stationary phase in bacterial cultures. CFA formation can thus be considered a conditional, postsynthetic modification of bacterial membrane lipid bilayers. This modification is noteworthy in several respects. It is catalyzed by a soluble enzyme, although one of the substrates, the UFA double bond, is normally sequestered deep within the hydrophobic interior of the phospholipid bilayer. The enzyme, CFA synthase, discriminates between phospholipid vesicles containing only saturated fatty acids and those containing UFAs; it exhibits no affinity for vesicles of the former composition. These and other properties imply that topologically novel protein-lipid interactions occur in the biosynthesis of CFAs. The timing and extent of the UFA-to-CFA conversion in batch cultures and the widespread distribution of CFA synthesis among bacteria would seem to suggest an important physiological role for this phenomenon, yet its rationale remains unclear despite experimental tests of a variety of hypotheses. Manipulation of the CFA synthase of Escherichia coli by genetic methods has nevertheless provided valuable insight into the physiology of CFA formation. It has identified the CFA synthase gene as one of several rpoS-regulated genes of E. coli and has provided for the construction of strains in which proposed cellular functions of CFAs can be properly evaluated. Cloning and manipulation of the CFA synthase structural gene have also enabled this novel but extremely unstable enzyme to be purified and analyzed in molecular terms and have led to the identification of mechanistically related enzymes in clinically important bacterial pathogens.

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