Enantioselective Saponification of Diacetates of 2‐Nitro‐1,3‐propanediols by Pig‐Liver Esterase and Preparation of Enantiomerically Pure Derivatives of 2‐Nitro‐allylic Alcohols (Chiral Multiple‐Coupling Reagents)The reproducible enantioselective saponification of open‐chain and cyclic diacetates ofmeso‐2‐nitro‐1,3‐propanediols (see4b–13b) with pig‐liver esterase (PLE) gives monoacetates (see4c–l3c) of>95% enantiomeric excess. TheReenantiotopic acetate group appears to be saponified preferentially, as proved by the X‐ray crystal structure analysis of three camphanoates4d,6d, and7d. Elimination of H2O or AcOH from the hydroxy acetates thus available gives derivatives of nitro‐allylic alcohols (see20–24,27, and29) which are subjected to diastereoselectiveMi