Photooxidation of citronitrile followed by esterification gives two new perfume prod-ucts: acetic esters of 2-methyl-6-formyl-1, 5-dieneheptanol-3 and 7-cyano-2, 6-dimethyl-3,6-dieneheptanol-2. The content of the secondary alcohol isomer in -ene type reaction ofcitronitrile has been found to be extremely low. Formation of 2-formyltetrahydrofuran, theprecursor of 2-methyl-6-formyl-1,5-diene-3-heptyl acetate, might proceed via ketoneoxidation mechanism of the secondary alcohol. In order to confirm the proposed mechanism,the disappearance rate constants of citronitrile, linalool acetate have been determined by com-parison with the photooxidation rate constant of 2,3-diphenyl-p-hexadioxene-2. A tetrapterouscorrelation diagram of C-2 double bond photooxidation of cis- and trans-citronitriles has beenused to interpret our observations. The difference in the rate constants of cis- and trans-citronitriles provides new evidence supporting the stepwise mechanism of -ene type reactionof singlet oxygen. Photooxidation of citronitrile followed by esterification gives two new perfume prod-ucts: acetic esters of 2-methyl-6-formyl-1, 5-dieneheptanol-3 and 7-cyano-2, 6-dimethyl-3,6-dieneheptanol-2 . The content of the secondary alcohol isomer in-ene type reaction of citronitrile has been found to be extremely low. Formation of 2-formyltetrahydrofuran, the precursor of 2-methyl-6-formyl-1,5-diene-3-heptyl acetate, might proceed via ketoneoxidation mechanism of the secondary alcohol. In order to confirm the proposed mechanism, the disappearance rate constants of citronitrile, linalool acetate have been determined by com-parison with the photooxidation rate constant of 2,3-diphenyl-p-hexadioxene-2 . The tetrapterouscorrelation diagram of C-2 double bond photooxidation of cis- and trans-citronitriles has beenused to interpret our observations. The difference in the rate constants of cis- and trans-citronitriles provides new evidence supporting the stepwise mechanism of -ene type reactionof singlet o xygen.