Electron Transfer Photochemistry of Chrysanthemol: An Intramolecular SN2‘ Reaction of a Vinylcyclopropane Radical Cation
摘要:
The electron transfer photochemistry of optically pure (1R,3S)-(f)-cis-chrysanthemol (cis-2) results in the formation of (R)-5-(1-(p-cyanophenyl)-1-methyethyl)-2,2-dimethyl oxacyclohex-3-ene (4) with significant retention of optical activity. The product is rationalized via nucleophilic attack of the alcoholic function of the radical cation on the terminal carbon of the vinyl group with simultaneous replacement of an isopropyl radical as an intramolecular leaving group in an apparent S(N)2' reaction. This mode of attack is unprecedented in vinylcyclopropane radical cations and is interpreted as evidence for the significant role that relief of ring strain and its avoidance play in determining the course of nucleophilic capture in radical cationic systems.
Site and Stereoselectivity of the Cyclopropanation of Unsymmetrically Substituted 1,3-Dienes by the Simmonssmith Reaction.<sup>+</sup>
作者:Mário César Guerreiro、Ulf Schuchardt
DOI:10.1080/00397919608002620
日期:1996.5
trans-vinylcyclopropane; an allylic hydroxyl group increases the reactivity and directs the cyclopropanation to the adjacent double bond. +Part of the results was presented at the XVIth InternationalConference on OrganometallicChemistry, Brighton, July 1994, abstract P228.