Facile Synthesis of Diastereoisomerically and Optically Pure 2-Substituted Hexahydro-1H-pyrrolizin-3-ones
作者:Romain Siegrist、Corinne Baumgartner、Paul Seiler、François Diederich
DOI:10.1002/hlca.200590158
日期:2005.8
that provides optically active 2-substituted hexahydro-1H-pyrrolizin-3-ones in four steps from commercially available Boc (tert-but(oxy)carbonyl))-protected proline. Diastereoisomers (−)-11 and (−)-12 were assembled from the proline-derived aldehyde (−)-8 and ylide 9via a Wittig reaction and subsequent catalytic hydrogenation (Scheme 3). Cleavage of the Boc protecting group under acidic conditions, followed
我们报告了一条短的合成路线,该路线可从市售Boc(叔-丁(氧)羰基))保护的脯氨酸中分四个步骤提供旋光的2-取代的六氢-1 H-吡咯烷-3-酮。非对映体( - ) - 11和( - ) - 12,从脯氨酸衍生的醛组装( - ) - 8和叶立德9经由一维悌希反应和随后的催化氢化(方案3)。在酸性条件下切割Boc保护基,然后进行分子内环化,得到所需的六氢-1 H-吡咯烷酮(-)- 1和(+)- 13。将相同的方案应用于内酯19,得到六氢-1 H-吡咯烷酮(-)- 25和(-)- 26(方案5)。目标化合物的绝对构型是通过NMR研究(图1和2)和X射线晶体学分析(图3)的组合来确定的。