Stereoselective Generation of 1‐Acyloxy‐2‐amino Carbanions by Deprotonation; Synthesis of Enantiomerically and Diastereomerically Pure β‐Amino Alcohols

Activation of the oxygen-substituted C atom so that it functions as a nucleophile—this is the key to the preparation of the stereoisomeric β-amino alcohols in pure form. The stereochemical outcome of the reactions of O-carbamate derivatives of achiral 2-(dibenzylamino)alcohols (e.g. 1 → 2) is determined by the reagent. If, on the other hand, a stereogenic center is in the β position, the stereochemistry of the deprotonation and the substitution is determined by the substrate. In both cases, the configurationally stable α-acyloxy-β-amino carbanion is the intermediate. El = electrophile.