Epoxynitrile Cyclization Research Articles

Humilisin E: Strategy for the Synthesis and Access to the Functionalized Bicyclic Core.

Humilisin E is a diterpenoid possessing a rare epoxidized cyclononene trans-fused with a bicyclo[3.2.0]heptane core. We have identified the P atropisomer of the corresponding cyclononadiene as a potential biosynthetic/synthetic precursor to humilisin E and reported two different strategies for the stereocontrolled synthesis of the appropriately functionalized bicyclic cores of humilisin E. The first route involves a Stork epoxynitrile cyclization via a Mg alkoxide, and the second, more stereoselective approach utilizes the Wolff rearrangement as the key step.

Synthetic Studies on Cyclocitrinol: Construction of the ABC Ring System Based on Epoxy–Nitrile Cyclization

AbstractThe stereoselective synthesis of a model compound containing the ABC ring system of cyclocitrinol was accomplished. After connecting a C ring allyltitanium segment with an A ring bi­cyclo[4.1.0]heptanone segment, the seven-membered B ring moiety was constructed by an intramolecular cyclization reaction of an epoxy nitrile. The enone moiety was introduced through an oxidative decyanation reaction, and the bicyclo[4.4.1]undecane skeleton with the highly strained olefin moiety was formed through a ring-opening reaction of the bicyclo[4.1.0]heptane substructure.

Total synthesis of (+/ − )-4-demethylenglerin A

Racemic 4-demethylenglerin A (1′), a simplified analog of the guaiane-type sesquiterpene englerin A (1), has been synthesized. The cyclic hydrocarbon core structure was built through modified Metz approach using epoxynitrile cyclization and direct Aldol reaction to prepare the precursor of RCM. The primary cytotoxicity test summarized that C4 methyl has marked impacts on the bioactivity.

Stereocontrolled Total Synthesis of (−)-Englerin A

The total synthesis of (-)-englerin A, a potent and selective inhibitor of renal cancer cell lines, is described. The key feature includes the stereocontrolled construction of the cyclopentane structure by taking advantage of a base-promoted epoxynitrile cyclization.

Synthesis of rumphellaone A via epoxy nitrile cyclization

The first enantioselective total synthesis of rumphellaone A, a cytotoxic 4,5-seco-caryophyllane isolated from the gorgonian coral Rumphella antipathies, has been achieved from a known olefinic alcohol by a 16-step sequence involving Stork's epoxy nitrile cyclization as the key step to concomitantly install a cyclobutane ring and three contiguous stereogenic centers contained in the molecule.

Enantioselective synthesis of rumphellaone A via epoxy nitrile cyclization

The first enantioselective synthesis of rumphellaone A, a cytotoxic 4,5- seco-caryophyllane derivative incorporating a γ-lactone ring as its structural feature, has been achieved by using base-induced intramolecular cyclization of an epoxy nitrile intermediate to install its cyclobutane skeleton as well as three contiguous stereocenters as the key transformation.

Enantioselective Formal Synthesis of Brefeldin A and Analogues via Anionic Cyclization of an Alkenyl Epoxide

Cyclopentene derivatives suitable as intermediates for syntheses of brefeldin A and analogues 6,7-dehydrobrefeldin C and norbrefeldin A were prepared by epoxynitrile cyclization of alkenyl epoxides.

Nitrile Anion Cyclization with Epoxysilanes Followed by Brook Rearrangement/Ring-Opening of Cyclopropane Nitriles/Alkylation

[reactions: see text] The reaction of delta-silyl-gamma,delta-epoxypentanenitrile derivatives 9-12 with a base and an alkylating agent affords (Z)-delta-siloxy-gamma,delta-unsaturated pentanenitrile derivatives via a tandem process that involves the formation of a cyclopropane derivative by epoxy nitrile cyclization followed by Brook rearrangement and an anion-induced cleavage of the cyclopropane ring. Exclusive formation of a (Z)-derivative from trans-epoxides is explained by the reaction pathway that involves a backside displacement of the epoxide by the alpha-nitrile carbanion and the O-Si bond formation followed by concerted processes involving Brook rearrangement and the anti-mode of eliminative ring fission of the cyclopropane from the rotamer 19. The fact that (E)-isomers are exclusively obtained from cis-epoxides and alpha-cyclopropyl-alpha-silylcarbinol derivative 26 provides experimental support for the proposed pathway.

Nitrile Anion Cyclization with Epoxysilanes Followed by Brook Rearrangement/Ring Opening of Cyclopropane Nitriles/Alkylation.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Nitrile anion cyclization with epoxysilanes followed by brook rearrangement/ring opening of cyclopropane nitriles/alkylation.

The reaction of delta-silyl-gamma,delta-epoxypentanenitrile derivatives with a base and an alkylating agent affords delta-siloxy-gamma,delta-unsaturated pentanenitrile derivatives via a tandem process that involves the formation of the cyclopropane derivative by epoxy nitrile cyclization followed by Brook rearrangement and an anion-induced cleavage of the cyclopropane ring.

Ring size in epoxynitrile cyclization. General synthesis of functionally substituted cyclobutanes. Application to (+-)-grandisol

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRing size in epoxynitrile cyclization. General synthesis of functionally substituted cyclobutanes. Application to (+-)-grandisolGilbert Stork and Jonathan F. CohenCite this: J. Am. Chem. Soc. 1974, 96, 16, 5270–5272Publication Date (Print):August 1, 1974Publication History Published online1 May 2002Published inissue 1 August 1974https://doi.org/10.1021/ja00823a053RIGHTS & PERMISSIONSArticle Views1449Altmetric-Citations136LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (356 KB) Get e-Alerts Get e-Alerts

Epoxynitrile cyclization. General method of ring formation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEpoxynitrile cyclization. General method of ring formationGilbert Stork, Lovji D. Cama, and D. R. CoulsonCite this: J. Am. Chem. Soc. 1974, 96, 16, 5268–5270Publication Date (Print):August 1, 1974Publication History Published online1 May 2002Published inissue 1 August 1974https://doi.org/10.1021/ja00823a052RIGHTS & PERMISSIONSArticle Views988Altmetric-Citations93LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (361 KB) Get e-Alerts Get e-Alerts