A Novel Pathway in the Photooxygenation of Cyclic Allenes
journal contributionposted on 27.04.2000, 00:00 by Ihsan Erden, Jiangao Song, Weiguo Cao
The photooxidation of cyclic allenes gives rise to cyclic 1,2,3-trione hydrates. The formation of these compounds points to a novel photooxidation mechanism involving both singlet and triplet oxygen. Upon placement of a methyl group on the allene, the mechanism shifts to predominantly an “ene” reaction. The corresponding cycloadditions with 4-methyl-1,3,4-triazoline-3,5-dione (MTAD) with cyclic allenes involve 2 equiv of MTAD. The dipolar intermediates are trapped with H2O to give α-urazole-substituted 2-cycloalkenones.