Highly stereoselective aldol reactions of titanium enolates from ethyl α-silyloxyalkyl ketones
作者:Sergi Figueras、Ricardo Martín、Pedro Romea、Fèlix Urpí、Jaume Vilarrasa
DOI:10.1016/s0040-4039(97)00108-1
日期:1997.3
Aldol-like reactions of titanium enolates derived from α-OH, α-OBn, and α-OTBS ketones with a series of aldehydes have been studied. In sharp contrast to the O-benzyl derivatives, the TBS-protected ketones lead to excellent yields and selectivities ( ratios from 30:1 to >95:1) even for the lactate-derived substrate (2-tert-butyldimethylsilyloxy-3-pentanone).
研究了衍生自α-OH,α-OBn和α-OTBS酮的烯醇钛酸酯与一系列醛类的醛醇缩合反应。与O-苄基衍生物形成鲜明对比的是,即使对于乳酸衍生的底物(2-叔丁基二甲基甲硅烷氧基-3-戊酮),TBS保护的酮也可产生出色的收率和选择性(比率从30:1到> 95:1)。)。