β-lithiation of oxazolinyloxiranes: Synthetic utility

Abstract

β-Lithiated oxazolinyloxirane 13a, generated by deprotonation of (R*, R*) trisubstituted oxazolinyloxirane 12a with s(-BuLi/TMEDA in Et2O at -100 °C, was found to be chemically and configurationally stable for at least 1 h at this temperature and reacted stereospecifically with electrophiles to give the corresponding tetrasubstituted derivatives 14a-j with complete retention of configuration at the β-carbon.