classical concepts5*6 and especially in nonoxidative cyclization processes for terpene biosynthesis.' Whereas irradiation of trans-caryophyllene (1) in homogeneous solution (CH&N/water 20/1) in the presence of an electron acceptor such as 1-cyanonaphthalene (1-CN) or 1,Cdicyanobenzene (1,4-DCB) causes merely ( E ) / ( Z ) isomerization (1 F? 2), competing transannular cyclization, affording 38*9 and 4,8,9