Synthesis of 5-endo-, 5-exo-, 6-endo- and 6-exo-hydroxylated analogues of epibatidine

摘要

A convenient, high-yield synmthesis of N-Boc-7-azabicyclo [2.2.1] hept-5-en-2-one (7) was developed by SmI_2-mediated desulfonylation of 6. Thus, 5-endo-, 5-exo-, 6-endo-, and 6-exo-hydroxylated epibatidine analogues 2a, b and 3a,b were synthesized from 7 by using a Pd (PPh_3)_4-catalyzed reductive Heck coupling reaction and SmI_2-mediated reduction of the carbonyl group as the key stps. Other reaction conditions for the reductive Heck procedure and the reduction step were also investigated.