Synthesis of (+)- and (-)-N-BOC-7-Azabicyclo[2.2.1]heptan-2-ones, Versatile Intermediates for the Enantiospecific Synthesis of (+)- and (-)-Epibatidine and Analogs
作者:Andres Hernandez、Manuel Marcos、Henry Rapoport
DOI:10.1021/jo00114a015
日期:1995.5
(+)- and (-)-Epibatidine, nonopiate antinociceptive alkaloids, have been prepared from (-)- and (+)-N-BOC-7-azabicyclo[2.2.1]heptan-2-one which were produced by resolution of the racemic mixture of the corresponding alcohols obtained in the previous racemic synthesis. In the present work, we report the enantiospecific synthesis of(-)- and (+)-N-BOC-7-azabicyclo[2.2.1]heptan-2-one from L-glutamic acid and levulinic acid. Also, this report describes the selective formation of trans-2,3-disubstituted-7-azabicyclo[2.2.1]heptanes from N-benzyl-5-(1'-methoxycarbonyl-3'-oxobutyl)proline via a decarbonylation/iminium ion cyclization process. These functionalized intermediates are of potential value for the enantiospecific synthesis of epibatidine analogues.
(+)-和(-)-表瑟啶((+)-和(-)-Epibatidine),作为非阿片类抗痛觉碱基,在本研究中已由(-)-和(+)-N-BOC-7-氮杂双环[2.2.1]庚烷-2-酮合成。这些酮类化合物是通过对相应光学活性醇类的消旋混合物进行拆分而获得的,之前的研究已实现该消旋合成。在本研究中,我们报告了通过L-谷氨酸和戊二酸(levulinic acid)对映选择性合成(-)-和(+)-N-BOC-7-氮杂双环[2.2.1]庚烷-2-酮的方法。此外,本报告还描述了通过N-苯甲基-5-(1'-甲氧基羰基-3'-氧代丁基)脯氨酸,经脱羰/亚胺离子环化过程选择性制备反式-2,3-二取代-7-氮杂双环[2.2.1]庚烷的过程。这些功能化中间体在表瑟啶类似物的对映选择性合成中具有潜在价值。