Ring Size Effect on Photochemical Cycloaddition of Enones with Cyclic Olefins

Article abstract of DOI:10.1246/bcsj.61.1416

Photochemical reaction of 3-substituted 2-cyclohexen-1-ones with methyl cyclohexene-1-carboxylate gave only head-to-tail, cis-transoid-cis photoadduct.The photoadducts of 3-methyl-2-cyclohexen-1-one with methyl-1-cyclopentene-1-carboxylate and with methyl 1-cyclobutene-1-carboxylate had head-to-head, cis-transoid-cis ring system.