[formula: see text] This report describes a new method to prepare optically active methylphenidate starting from piperidine. The method consists of a transformation of N-methoxycarbonylpiperidine to the corresponding alpha-methoxylated carbamate I by utilizingelectrochemicaloxidation followed by the coupling reaction with optically active Evans imides II to produce optically active methylphenidate
[公式:见正文]该报告介绍了一种从哌啶开始制备旋光哌醋甲酯的新方法。该方法包括通过利用电化学氧化将N-甲氧基羰基哌啶转化为相应的α-甲氧基化氨基甲酸酯I,然后与旋光的Evans酰亚胺II偶联反应,以生产具有高立体选择性苏氨酸-(2R,2可以通过三步轻松地从III制备R'-哌醋甲酯(IV; Ar = Ph;利他林)。
Asymmetric synthesis of optically active 2,3-diarylsuccinic acids by oxidative homocoupling of chiral 3-(arylacetyl)-2-oxazolidones
Oxidative homocoupling of chiral 3-(arylacetyl)-2-oxazolidones 1 was achieved by treatment with DABCO-TiCl4 or DMAP-TiCl4 and afforded the corresponding dimers stereospecifically. The reaction of (4S)- and (4R)-substituted 1 gave (S,S)- and (R,R)-dimers respectively. The obtained dimers were easily transformed to the corresponding 2,3-diaryl succinic acids. This reaction therefore provides a useful
A Convenient Method for Synthesis of Optically Active Methylphenidate from N-Methoxycarbonylpiperidine by Utilizing Electrochemical Oxidation and Evans Aldol-type Reaction
A new method to prepare optically active methylphenidate starting from piperidine is described. The method consists of a transformation of N-methoxycarbonylated piperidine to the corresponding alpha-methoxylated carbamate utilizing electrochemical oxidation followed by the coupling reaction with optically active Evans imides to produce optically active methylphenidate derivatives with high stereoselectivity (erythrolthreo=5.3/94.7, the three isomer; 99.6%ee). (C) 2000 Elsevier Science Ltd. All rights reserved.