Enones with Strained Double Bonds. 4. The Bicycloundecane System

Article abstract of DOI:10.1021/jo01298a012

Bicyclo<5.3.1>undec-7-en-9-one (2) has been synthesized from cyclooctenone.This bicyclo<5.3.1> enone system 2 shows less tendency to add nucleophiles in a conjugate manner than is the case for the more strained bicyclo<4.3.1>enone 3 and bicyclo<3.3.1> enone 4.Comparison of the ultraviolet spectra and the electrochemical reduction potentials of the monocyclic enone 1 and the bicyclic enones 2 and 3 indicates that these compounds absorb light at longer wavelengths and that they are more easily reduced to the corresponding anion radicals as distortion of the conjugated enone system increases.Force field calculations have been used to estimate the degree of distortion present in the enone systems of these bicyclic compounds.