Synthesis of cardamom peroxide analogues by radical cyclization of hydroperoxyalkenes

Three pinenic hydroperoxides were synthesized according to the Dussault method. Two of them could cyclize under radical conditions to give the exo-trig isomer as a single regioisomer. Only five- and six-member ring peroxides were obtained, whereas none of the possible seven-member ones was observed. This strategy could be employed in the total synthesis of cardamom peroxide.