Stereospecific route to enantiopure all cis-2,3,6-trisubstituted piperidines. Facile synthesis of (−)-deoxocassine and (+)-azimic acid
作者:Dawei Ma、Nan Ma
DOI:10.1016/s0040-4039(03)00820-7
日期:2003.5
of the enantiopure β-amino esters 10 provides the γ-amnio alcohol 11, which is condensed with 2,4-pentadione to afford 12. Stepwise cyclization of 12 produced the cyclic enamine 13, which is hydrogenated to deliver all cis-2,3,6-trisubstituted piperidine 14. Using this reaction sequence and subsequent Baeyer–Villiger oxidation as the key step (−)-deoxocassine and (+)-azimic acid are synthesized.
对映体纯的β-氨基酯10的还原提供了γ-氨醇11,将其与2,4-戊二酮缩合得到12。12的逐步环化产生环状烯胺13,其被氢化以递送所有顺式-2,3,6-三取代哌啶14。使用该反应顺序和随后的Baeyer-Villiger氧化作为关键步骤,可以合成(-)-脱氧卡西汀和(+)-叠氮酸。