A novel pathway in the photooxygenation of cyclic allenes.
[equation--see text] 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 H(2)O to give alpha-urazole-substituted 2-cycloalkenones.
Erden
I
I
San Francisco State University, Department of Chemistry and Biochemistry, San Francisco, California 94132, USA. ierden@sfsu.edu
Song
J
J
Cao
W
W
D000475:Alkenes / Q000737:chemistry*; D006844:Hydrocarbons, Cyclic / Q000737:chemistry*; D015394:Molecular Structure; D010100:Oxygen; D010777:Photochemistry; D026082:Singlet Oxygen; D013329:Structure-Activity Relationship
D000475:Alkenes; D006844:Hydrocarbons, Cyclic; D026082:Singlet Oxygen; D010100:Oxygen