Synthese cyclopropenique totale d'un triquinane naturel lineaire, le (±)-hirsutene

The cycloaddition of enamines with electrophilic gem-dimethylcyclopropenes followed by solvolytic ring cleavage of the 2-amino bicyclo [2.1.0] pentane adducts, leads to gem-dimethylcyclopentene derivatives. This novel reaction sequence is illustrated by the synthesis of (±)-Hirsutene, a natural linear triquinane, starting from 3,3-dimethylcyano-cyclopropene and the diquinane enamine 3.