作者:Franklin A. Davis、Tianan Fang、Bin Chao、David M. Burns
DOI:10.1055/s-2000-8710
日期:——
The asymmetric synthesis of all four stereoisomers of 4-hydroxypipecolic acid (1) from the polyfunctionalized chiral building blocks δ-amino β-keto esters (S S, R)-(+)-5 or (R s, S)-(-)-5 is described. Key steps in the synthesis are the stereoselective reductions of b-phenylpiperidine-2,4-dione (6) and N-sulfinyl δ-amino β-keto esters 5 to cis-4-hydroxy 2-piperidinone 7 and syn-δ-amino β-hydroxy ester 9, respectively. The only protecting/deprotecting group chemistry required is related to the oxidation step.
描述了从多功能手性构建块 δ-氨基 β-酮酯 (S S, R)-(+)-5 或 (R s, S)-(-)-5 不对称合成4-羟基皮克酸 (1) 的四种立体异构体。合成的关键步骤是对 β-苯基哌啶-2,4-二酮 (6) 和 N-亚砜基 δ-氨基 β-酮酯 5 的立体选择性还原,分别得到顺式的4-羟基-2-哌啶酮 7 和 syn-δ-氨基 β-羟基酯 9。所需的唯一保护/去保护基团化学与氧化步骤有关。