SN2′ addition/1,2-elimination of dimethylsulfonium methylide with epoxy vinyl sulfones: synthesis of exocyclic cross-conjugated dienyl sulfones
作者:Vikas Sikervar、Philip L. Fuchs
DOI:10.1039/c0cc05405d
日期:——
Dimethylsulfoniummethylide undergoes S(N)2' addition/1,2-elimination with epoxy vinylsulfones to generate enantiopure six and seven membered cross-conjugated hydroxy vinylsulfones. Moderate to excellent yields were obtained for both six and seven membered substrates.
Lactol-Directed Osmylation. Stereodivergent Synthesis of Four C-19,20 Apoptolidin Diols from a Single Allylic Hemiacetal
作者:Youngsoon Kim、Philip L. Fuchs
DOI:10.1021/ol0707564
日期:2007.6.1
A synthetic approach to prepare four Apoptolidin C-19,20 diastereomeric diol derivatives was developed. Two diastereomers were obtained from the (Z)-form, which is converted to the (E)-form, followed by dihydroxylation to deliver two more diastereomers. The (E)-allylic hemiacetal and methoxyacetal showed opposite diastereoselectivity.