Synthesis, asymmetric aldol reactions, and x‐ray crystallography of some oxadiazinanone derivatives

Abstract

Abstract magnified image A series of N 4 ‐substituted oxadiazinanones have been synthesized from (1 R ,2 S )‐norephedrine by a process of either reductive alkylation or arylation, N ‐nitrosation, reduction and cyclization. These derivatives (R = ‐CH 2 Ph, ‐CH 2 C(CH 3 ) 3 , ‐ cyclo ‐C 6 H 11 , ‐C 6 H 5 ) have been acylated with propanoyl chloride and employed in the asymmetric Aldol reaction. The observed diastereoselectivities for the formation of the “non‐Evans” syn‐adduct ranged from 88:12 to 99:1. The hydrolysis of the Aldol adducts varied with the nature of the nitrogen substituent.