Chiral Lithium‐1‐oxyalkanides by Asymmetric Deprotonation; Enantioselective Synthesis of 2‐Hydroxyalkanoic Acids and Secondary Alkanols

Abstract

A Very simple general, solution to the problem of preparing chiral synthons of the type 3 is provided by the lithium complexes 1. They are generated by asymmetric deprotonation of the corresponding prochiral “non-activated” alkyl carbanates with sec-butyllithium/(–)-sparteine. 1 can be substituted by electrophiles stereospecifically to give the protected hydroxy-derivatives 2 (> 95 ee), and the Cbx group is readily cleavable. R1  alkyl, Cbx  carbamoyl idue of 1.