Protonation and gem-diol formation of 1-azaadamantanones

Abstract

Protonation and ketone hydration of 1-azaadamantane-monoketone, -diketone, and -triketone (3,5,7-trimethyl-1-azatricyclo[3.3.1.1^3,7]decan-4-one, -4,6-dione, and -4,6,10-trione, respectively) has been studied applying spectrophotometric and stopped-flow techniques. The very fast protonation is coupled to the slow keto/gem-diol transformation. The through bond interaction between the nitrogen and the carbonyl groups influences strongly the basicity of the nitrogen lone pair. gem-Diol formation is favoured by the steric stress in the adamantane skeleton caused by the carbonyl groups.