β,γ-二取代γ-内酯的不对称合成

Asymmetric Synthesis of β,γ-Disubstituted γ-Lactones

报道一种从 (S) 苹果酰呀亚胺出发合成 β ,γ 二取代γ 内酯灵活方法 .该法可用于合成 ( 3R ,4S) blastmycinone ,反式 whisky内酯及相关天然内酯 .通过格氏加成引入γ 侧链使本法兼具多用性和灵活性 .

A flexible approach to γ-alkyl β-htdroxy γ-lactone is described. Tow of the lactones were converted into blastmycinone and trans-whisky lactone respectively. The method features a NaBH4 mediated reductive ring-opening of N,O-acetals, which is obtained via a regioselective Grignard reagent addition with (S)-N,O-dibenzylmalimide followed by lactoneization. The flexibility of the method allows the introduction of various γ-alkyl side chains by Grignard reagents addition.