1: 3,3-dimethyl-5-phenyldihydrofuran-2(3H)-one With diisobutylaluminium hydride in dichloromethane; toluene T=-78°C; 2 h; 2: acetic anhydride With pyridine; 4-(N,N-dimethlyamino)pyridine in dichloromethane; toluene T=-78 - 22°C; 12 h;