Accès au squelette triquinanique linéaire par l'intermédiaire de dérivés bicyclo [2.1.0] pentaniques. Synthèse totale d'un triquinane, le (±) hirsutène.

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. These reactions are used as key-sequence for the synthesis of Hirsutene, a natural linear triquinane, starting from the cyanocyclopropene 18 and the diquinane enamine 15. The cis-anti-cis-anti-cis structure of the intermediate quadricyclic adduct 20b, containing the bicyclo [2.1.0] pentane substructure, was proved by an X-ray crystallographic determination.