Synthesis of Enantiopure Dihydropyranones: Aldol-Based Ring Expansion of Dihydrofurans
作者:Timothy J. Donohoe、Ali Raoof、Graeme C. Freestone、Ian D. Linney、Andrew Cowley、Madeleine Helliwell
DOI:10.1021/ol0263595
日期:2002.9.1
this process to an oxidative cleavage/aldol ring closure sequence we were able to produce highly functionalized and enantiopure dihydropyranones in high yield. This sequence has ample flexibility built into it, either by the use of different electrophiles during reductive alkylation or by subsequent derivatization of the dihydropyranone after ring expansion.
[反应:见正文]描述了使用容易获得的手性助剂对3-甲基-2-糠酸进行立体选择性Birch还原;通过将这一过程与氧化裂解/醛环闭合序列相结合,我们能够以高收率生产高度官能化和对映体纯的二氢吡喃酮。通过在还原烷基化过程中使用不同的亲电试剂或在扩环后随后将二氢吡喃酮衍生化,该序列具有足够的灵活性。