1: 70 percent / DDQ, 2,4,6-collidine / benzene / 7 h / 0 - 3 °C 2: 87 percent / triethyl amine, 4-(dimethylamino)pyridine / 72 h / -20 °C View Scheme

1: 70 percent / DDQ, 2,4,6-collidine / benzene / 7 h / 0 - 3 °C 2: 1) tert-BuOK / 1) THF; 2) ether, -100 degC, 4 h View Scheme