Three methods for preparing secondary azacyclononanes from 9-substituted indolizidines were investigated. The first method utilized previously developed ring-opening reactions to give AT-benzylazacyclononanes, which were debenzylated by cleavage with alkyl chloroformates. N-Benzyl-5-ethylideneazacyclononane (8) was converted to 11 in this way via either the ethyl or the 2, 2, 2-trichloroethyl carbamate. The former group was removed ...
