Oxidative transformations of cembrane diterpenoids III. Epoxycembrenes

Summary 1. It has been established that the epoxidation of cembrene with perbenzoic and peracetic acids takes place stereospecifically at each of the trisubstituted double bonds with the formation of 4S,5R-, 7S,8S-, and 11S,12S-monoepoxycembrenes, the structures and absolute configurations of which have been established by spectral methods.2. Epoxidation of cembrene at the C₁₁–C₁₂ double bonds under the conditions used takes place preferentially as compared with epoxidation at the C₇–C₈ double bond.Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Novosibirsk State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 525–531, July–August, 1977.