Convenient new synthesis of snoutene [1] utilizing a dipolar cycloaddition of 4-phenyl-1,2,4-triazolin-3,5-dione

Article abstract of DOI:10.1016/S0040-4039(00)92793-X

4-Phenyl-1,2,4-triazolin-3,5-dione readily cycloadds to Nenitzescu's hydrocarbon 1 ^[6] with skeletal rearrangement. The major adduct 6 can conveniently be transformed to the azo compound 8, which upon photolysis or thermolysis yields up to 80 % pentacyclo[3.3.2.0^2,4,.0^3,7.o^6,8]dec-9-ene (" snoutene ").