Approaches to the synthesis of (2R,3S)-2-hydroxymethylpyrrolidin-3-ol (CYB-3) and its C(3) epimer: a cautionary tale
作者:Alison N. Hulme、Karen S. Curley
DOI:10.1039/b200415a
日期:2002.4.9
The syntheses of (2R,3S)-2-tert-butyldiphenylsilyloxymethylpyrrolidin-3-ol (TBDPS-protected CYB-3) (21) and its C(3) epimer (25) have been achieved in 9 and 8 steps respectively from D-serine. However, chiral HPLC analysis of the key β-hydroxy ester intermediates in these syntheses (17 and 18) revealed that appreciable levels of racemisation had occurred in the aldol and Claisen condensation reactions used in this synthetic sequence.
(2R,3S)-2-叔丁基二苯基硅氧基甲基吡咯烷-3-醇(TBDPS保护的CYB-3)(21)及其C(3)差向异构体(25)的合成从D开始分别经过9步和8步完成-丝氨酸。然而,对这些合成中关键 β-羟基酯中间体(17 和 18)的手性 HPLC 分析表明,在该合成序列中使用的羟醛和克莱森缩合反应中发生了明显水平的外消旋化。