Synthesis of (+)- and (-)-N-BOC-7-azabicyclo[2.2.1]heptan-2-ones, versatile intermediates for the enantiospecific synthesis of (+)- and (-)-epibatidine and analogues

Article abstract of DOI:10.1021/jo00114a015

(+)- 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'-exobutyl)proline via a decarbonylation/iminium ion cyclization process. These functionalized intermediates are of potential value for the enantiospecific synthesis of epibatidine analogues.