A convenient method for synthesis of optically active methylphenidate fromN-methoxycarbonylpiperidine by utilizing electrochemical oxidation and Evans aldol-type reaction

A new method to prepare optically active methylphenidate starting from pipe ridine is described. The method consists of a transformation of N-methoxyca rbonylated piperidine to the corresponding alpha-methoxylated carbamate uti lizing electrochemical oxidation followed by the coupling reaction with opt ically active Evans imides to produce optically active methylphenidate deri vatives with high stereoselectivity (erythrolthreo=5.3/94.7, the three isom er; 99.6%ee). (C) 2000 Elsevier Science Ltd. All rights reserved.