Cyclization of 1,<i>n</i>-Enynes Initiated by the Addition Reaction of <i>gem</i>-Dichromiomethane Reagents to Alkynes
作者:Masahito Murai、Ryuji Taniguchi、Kazuhiko Takai
DOI:10.1021/acs.orglett.0c01304
日期:2020.5.15
Treatment of 1,n-enynes with gem-dichromiomethane species prepared in situ from 1,1-diiodomethanes and CrCl2 gave alkenylbicycloalkanes. Alkenylcarbene species, which was generated via [2 + 2] cycloaddition with a triple bond, were intercepted by intramolecular cyclopropanation of a pendant double bond, and alkene metathesis did not proceed. This is a very rare example of transformation of alkynyl
Ring-Opening Reaction of Methylenecyclopropanes Derived from Methylenecyclopropyl Aldehydes through Cope Rearrangement
作者:Xiang-Ying Tang、Yin Wei、Min Shi
DOI:10.1002/ejoc.201000880
日期:2010.11
Tandem Wittig reaction/Cope rearrangement of methylenecyclopropyl aldehydes 1 with cinnamyltriphenylphosphonium bromide afforded a convenient method for the synthesis of cyclopentene derivatives 2 in moderate yields in a one-pot manner. Dialkyl 2-[(2-methylenecyclopropyl)methylene]malonates 3 derived from methylenecyclopropyl aldehydes 1 could produce two kinds of cyclopentene derivatives, 4 and 5