(±)-N-叔丁氧羰基-3-乙基-戊氨酸的合成

Synthesis of(±)-N-Boc-3-ethyl-norvaline

在最优反应条件[海因2 mmol,n(3-戊酮)∶n(海因)=1.5,乙醇胺为碱,p H 4,于55℃反应6 h]下制得5-(1-乙基亚丙基)海因(4);4用5%Pd/C催化加氢制得5-(3-戊基)海因(5);5先在碱性条件下水解,再通过叔丁氧羰基保护氨基合成了(±)-N-叔丁氧羰基-3-乙基-戊氨酸,总收率43%,其结构经~1H NMR,^(13)C NMR和HR-ESI-MS确证。

5-（ Pentan-3-ylidene） imidazolidine-2,4-dione（ 4） was obtained at 55 ℃ for 6 h under the optimized reaction conditions[hydantoin 2 mmol,n（ 3-pentanone） ∶ n（ hydantoin） = 1. 5,cholamine as base,p H 4]. 5-（ Pentan-3-yl） imidazolidine-2,4-dione（ 5） was prepared with hydrogenation of 4 by 5%Pd/C.（ ±）-N-Boc-3-ethyl-norvaline was synthesized by hydrolyzation of 5 in alkaline condition,and then N-Boc protection reaction. The structure was confirmed by^1 H NMR,^（13）C NMR and HR-ESI-MS.