Easy and Stereoselective Approach to α,β-Unsaturated γ-Lactones Fused to Pyranoses from Furanose Scaffolds
作者:Nuno M. Xavier、Amélia P. Rauter
DOI:10.1021/ol071351m
日期:2007.8.1
The first facile and efficient route to pyranose-fused butenolides from furanose scaffolds, convenient for scaling up production, is described. Wittig olefination of 1,2-O-isopropylidene pentofuranos- or hexofuranos-3-uloses with a resonance-stabilized ylide led to the stereoselective formation of the (Z)-alpha,beta-unsaturated ester. In the presence of acid labile 5-O- or 5,6-di-O-protecting groups
描述了从呋喃糖支架向吡喃糖融合的丁烯内酯的第一种简便有效的途径,该途径便于扩大生产。1,2-O-异亚丙基戊呋喃糖或六呋喃糖-3-ul的Wittig烯烃与共振稳定的基团的反应导致(Z)-α,β-不饱和酯的立体选择性形成。在酸不稳定的5-O-或5,6-二-O-保护基的存在下,Wittig产物的酸水解导致异构化为吡喃糖形式和自发内酯化,从而以良好的总收率得到目标分子。