Direct Asymmetric Allylic Alkylation of Butenolides with Morita−Baylis−Hillman Carbonates
作者:Hai-Lei Cui、Ji-Rong Huang、Jie Lei、Zhao-Feng Wang、Shi Chen、Li Wu、Ying-Chun Chen
DOI:10.1021/ol100014m
日期:2010.2.19
The direct asymmetric allylic alkylation of β,γ-butenolides with MBH carbonates to access γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary chiral centers has been presented in excellent stereoselectivities (86−96% ee, dr >95:5) and moderate to good yield (50−83%). Their synthetic utility has been well demonstrated by the facile construction of bicyclic lactones bearing 4−5
β,γ-丁烯内酯与MBH碳酸酯的直接不对称烯丙基烷基化反应可进入包含相邻季铵和叔手性中心的γ,γ-二取代丁烯醇酯,且立体选择性极好(86-96%ee,dr> 95:5)达到良好的收率(50-83%)。它们的合成效用已通过轻松构建带有4-5个立体生成中心的双环内酯得到充分证明。