An olefination approach to the enantioselective syntheses of several styryllactones
作者:Joel M Harris、George A O'Doherty
DOI:10.1016/s0040-4020(01)00355-6
日期:2001.6
Sharpless catalytic asymmetric dihydroxylation to vinylfuran. The resulting diols are produced in high enantioexcess and can be stereoselectively transformed into α,β-unsaturated-δ-lactones via a short highly diastereoselective oxidation and reduction sequence. Wittig olefination or Julia olefination reactions were used to introduce the phenyl group side chain either cis or trans selectively and these
到高度官能化的α,β不饱和δ内酯的柔性对映选择性途径,已经允许用于styryllactones的合成:altholactone,isoaltholactone,3-外延-altholactone,2-外延-altholactone和5-羟基goniothalamin在2.5,10,糠醛的总收率分别为5%,1%和13%。通过将Sharpless催化不对称二羟基化反应应用于乙烯基呋喃,此方法可得出其不对称性。所产生的二醇以高对映体过量产生,并且可以通过短的高度非对映选择性氧化和还原序列立体选择性地转化为α,β-不饱和-δ-内酯。使用维蒂希(Wittig)烯化或朱莉娅(Julia)烯化反应来引入顺式或反式的苯基侧链 选择性地将这些中间体通过选择性环氧化反应进一步精制为内酯异构体。