1: 74 percent / nBuLi / hexamethylphosphoric acid triamide; tetrahydrofuran / -100 °C 2: 72 percent / 6 N HCl / Heating View Scheme

1: 66 percent / nBuLi / hexamethylphosphoric acid triamide; tetrahydrofuran / -100 °C 2: 90 percent / KH / tetrahydrofuran / -78 °C 3: 1) MeI, 2) 6 N HCl / 1) 60 deg C, 2) r.t., 5 min View Scheme

1: 66 percent / nBuLi / hexamethylphosphoric acid triamide; tetrahydrofuran / -100 °C 2: 88 percent / KH / tetrahydrofuran / -78 °C 3: 68 percent / O3 / CH2Cl2 / -78 °C View Scheme