Three types of photosensitized oxygenations of α-cedrene (CED) were investigated, including: rose bengal( RB)-sensitized photooxygenation of α-cedrene in acetonitrile produced one major stereospecific product (cedr-8- exoen-9α-ol), in which the double bond migrated to an adjacent position, this result demonstrated the singlet oxygen process; 9,10-dicyanoanthrathene (DCA) sensitized photooxygenation