Asymmetric Synthesis of Intermediates for Otamixaban and Premafloxacin by the Chiral Ligand-Controlled Asymmetric Conjugate Addition of a Lithium Amide
作者:Takeo Sakai、Yoshito Kawamoto、Kiyoshi Tomioka
DOI:10.1021/jo060588d
日期:2006.6.1
A chiral ligand-controlled conjugateaddition reaction of lithium benzyl(trimethylsilyl)amide with tert-butyl enoates gave the corresponding lithium enolates that were then treated with electrophiles, giving anti-alkylation products with high ee up to 98%. The benzyl group on the amino nitrogen was removed by the oxidation of secondary amines to imines and subsequent transoximation to give 3-aminoalkanoates