Enantiomerically pure 2-alkyl and 2,3-dialkylaziridines from 2-sulfinylimines

A new entry to optically pure aziridines from N-p-methoxyphenyl derivatives of 2-p-tolylsulfinylketimines is reported. The highly stereoselective redu ction of the imines with DIBAL=H/ZnX2 yielded the corresponding sulfinyl am ines, which can be transformed into the N-Cbz derivatives through a two-ste p sequence involving reaction with BnO2CCl and subsequent oxidation with CA N. These compounds were easily transformed into optically pure aziridines b y reduction of the sulfinyl group, further methylation at sulfur, and final cyclization with base. (C) 1998 Elsevier Science Ltd. All rights reserved.