Mechanistic Aspects of Gas-Phase Photodecarbonylation Reactions of Bicyclohexanones

Article abstract of DOI:10.1021/jo01298a004

The gas-phase photodecarbonylation and photofragmentation reactions of substituted bicyclo<3.1.0>hexan-3-ones have been studied in detail.Photolysis of these ketones yields 1,3-dienes, vinylcyclopropanes, and 1,4-dienes as detectable products.The possible mechanisms for these reactions are discussed in light of the regiochemical and stereochemical results obtained.In addition, methyl substitution at C-6 and C-2 of these ketones has been shown to have a pronounced effect on both product ratios and overall reaction efficiency.These effects are discussed in terms of stereoelectronic and electronic controls of rates of cyclopropane ring opening of intermediate acylcyclopropylcarbinyl diradicals.