Enantiopure Synthesis of Side Chain-Modified α-Amino Acids and 5-<i>cis</i>-Alkylprolines
作者:Amar R. Mohite、Ramakrishna G. Bhat
DOI:10.1021/jo300653u
日期:2012.6.15
concise synthesis of enantiopure, side chain-modified α-amino acids such as 4-oxo-l-norvaline, 6-oxo-l-homonorleucine, and 5-cis-alkyl prolines is described. Knoevenagel condensation of l-aminocarboxylate-derived β-ketoesters with aldehydes followed by reductive decarboxylation results in unnatural α-amino acids in good yield. A fluorescent amino acid is synthesized using a similar protocol. These studies
描述了对映体纯的,侧链修饰的α-氨基酸(例如4-氧-1-降冰片碱,6-氧-1-升-亮氨酸和5-顺-烷基脯氨酸)的简短的简明合成。1-氨基羧酸酯衍生的β-酮酸酯与醛的Knoevenagel缩合,然后进行还原性脱羧,从而以高收率得到非天然的α-氨基酸。使用类似的方案合成荧光氨基酸。这些研究表明,氨基羧酸酯衍生的β-酮酸酯是非常有用的中间体,所采用的方法对于制备γ(δ)-氧代α-氨基酸和烷基脯氨酸既通用又实用。