Sequential diastereoselective addition and allylic azide isomerization of syn- and anti-.alpha.-azido-.beta.-(dimethylphenylsilyl)-(E)-hex-4-enoates with acetals: asymmetric synthesis of .gamma.-hydroxy-.alpha.-amino acid synthons
作者:James S. Panek、Michael Yang、Itzhak Muler
DOI:10.1021/jo00041a002
日期:1992.7
syn- and anti-methyl alpha-azido-beta-(dimethylphenylsilyl)-(E)-hex-4-enoates (2R,3R)-1a and (2S,3R)-1b undergo highly diastereo- and enantioselective addition reactions with oxonium ions catalyzed by the action of trimethylsilyl trifluoromethanesulfonate (TMSOTf) to generate alpha-azido-beta,gamma-unsaturated esters 2, with well-defined 1,4- and 1,5-stereochemical relationships, and a subsequent stereospecific allylic azide isomerization generated 1,3-azido ethers 3, synthetic equivalents of gamma-hydroxy-alpha-amino acids.