[EN] GAMMA SECRETASE MODULATORS<br/>[FR] MODULATEURS DE GAMMA SECRÉTASE
申请人:SCHERING CORP
公开号:WO2010075204A3
公开(公告)日:2010-09-16
Metal-halogen exchange-initiated intramolecular conjugate addition reactions of conjugated acetylenic esters
作者:Manning P. Cooke
DOI:10.1021/jo00076a053
日期:1993.11
The lithium-iodine exchange-initiated intramolecular conjugate addition reactions of some model gamma-iodo-alpha,beta-acetylenic esters have been examined. Product mixtures arising from proton abstraction reactions were observed in reactions leading to 5-membered ring formation. More efficient cyclizations resulted when reactions were conducted in the presence of trimethylsilyl chloride to trap intermediate allenolate ions. Allenolate ion trapping by an internal electrophilic center in 26 resulted in the highly efficient formation of bicyclic ester 27.