Construction of Enantiomerically Enriched Tertiary α‐Hydroxycarboxylic Acid Derivatives by Phase‐Transfer‐Catalyzed Asymmetric Alkylation of Diaryloxazolidin‐2,4‐diones

Center of attention: The chiral ammonium bromide 1 has been used as a catalyst for the highly enantioselective alkylation of diaryloxazolidindiones 2 under mild phase-transfer conditions (TBME=tert-butyl methyl ether). This method provides practical access to a variety of optically active tertiary α-hydroxycarboxylic acid derivatives.