Reaction of 2-iodocyclohepta-2,4,6-trien-1-one with 1-azabicyclo[2,2,2]octane. An unusually easy nucleophilic opening of a bicyclo[2,2,2]octane skeleton

Abstract

1-Azabicyclo[2,2,2]octane (I) reacts with 2-iodo-cyclohepta-2,4,6-trien-1-one in benzene to give either 2-(4-β-1-azoniabicyclo[2,2,2]octane-ethylpiperidino)-cyclohepta-2,4,6-trien-1-one iodide (II) or 2-(1-azoniabicyclo[2,2,2]octane)cyclohepta-2,4,6-trien-1-one iodide (III), or a mixture of both according to reaction conditions; (III) is readily rearranged to 2-(4-β-iodoethyl-piperidino)cyclohepta-2,4,6-trien-1-one (IV).