Sequential diastereoselective addition and palladium(II)-catalyzed allylic acetate transposition of syn- and anti-.alpha.-acetoxy-.beta.-silyl-(E)-hex-4-enoates with achiral acetals. Asymmetric synthesis of differentiated syn and anti 1,3-diol synthons
作者:James S. Panek、Michael Yang、Jason S. Solomon
DOI:10.1021/jo00057a008
日期:1993.2
syn- and anti-methyl alpha-acetoxy-beta-(dimethylphenylsilyl)-(E)-hex-4-enoates, (2R,3R)-8a and (2S,3R)-8b, undergo highly diastereo- and enantioselective addition reactions with aldehydes and acetals 11 catalyzed by the action of trimethylsilyl trifluoromethanesulfonate (TMSOTf) generating alpha-acetoxy-beta,-gamma-unsaturated esters (allylic acetates) 12. A subsequent allylic acetate transposition promoted by dichloropalladium bisacetonitrile complex, PdCl2(MeCN)2 afforded the differentiated 1,3-diol synthons 13.