Efficient resolution of rac-2-cyano-2-methyl-3-phenylpropanoic acid. An appropriate starting material for the enantioconvergent synthesis of (S)-α-methylphenylalanine on a large laboratory scale
作者:Ramón Badorrey、Carlos Cativiela、Marı́a D. Dı́az-de-Villegas、José A. Gálvez
DOI:10.1016/s0957-4166(03)00450-6
日期:2003.8
A large laboratory scale synthesis of (S)-α-methylphenylalanine from benzaldehyde and methyl cyanoacetate has been developed. The synthesis is based on the following sequence: (i) preparation of racemic 2-cyano-2-methyl-3-phenylpropanoic acid, (ii) resolution of the enantiomers by crystallisation using norephedrine, and (iii) development of an efficient enantioconvergent synthesis of (S)-α-methylphenylalanine
已经开发了由苯甲醛和氰基乙酸甲酯合成(S)-α-甲基苯丙氨酸的大规模实验室规模。合成是基于以下顺序:(i)外消旋2-氰基-2-甲基-3-苯基丙酸的制备,(ii)使用去甲麻黄碱通过结晶拆分对映异构体,以及(iii)开发有效的对映收敛合成(的小号从对映体纯()-α甲基苯丙氨酸小号和( - )- [R)-2-氰基-2-甲基-3-苯基丙酸。实验程序的简单性,避免了低温反应,需要惰性气氛和柱色谱,再加上使用廉价且容易获得的试剂,使得该方法在合成上非常有吸引力。