Gold- vs. platinum-catalyzed polycyclizations by O-acyl migration. Solvent-free reactions

Polycyclic derivatives incorporating a cyclopropyl group have been efficiently synthesized from propargyl acetates using platinum(II), gold(I) and gold(III) catalysis. These reactions which are also viable for the preparation of medium-sized rings, proceed with a complete diastereocontrol and can also be run in neat conditions.