Molecular design by cycloaddition reactions. Part XIV. Ready chemical transformation of the bicyclo[3.2.2]nonadiene skeleton

Abstract

The pentacyclo[7.6.1.0^2,8.0^3,5.0^10,15]hexadecatetraen-4-ylacetamides (5b–d) and (6b–d) were easily prepared from the photoinduced reaction of compounds containing the bicyclo[3.2.2.]nonadiene skeleton (enone-π-methane system) in the presence of some amines in good yields. The dimethyl carboxamides (5d) and (6d) were converted into compounds containing the bicyclo[3.2.2]nona-2,6-diene skeleton, (10) and (11), by Hofmann degradation, followed by thermal [3,3] rearrangement (Cope rearrangement) probably via divinylcyclopropane intermediates.