1: 75 percent / potassium tert-butoxide / 2-methyl-propan-2-ol / 12 h / 25 °C 2: 90 percent / aq. NaOH / methanol / 8 h View Scheme

1: 75 percent / potassium tert-butoxide / 2-methyl-propan-2-ol / 12 h / 25 °C 2: 90 percent / aq. NaOH / methanol / 8 h 3: tetrahydrofuran / 1 h / 25 °C View Scheme

pyridine in diethyl ether; dichloromethane 2 h; Ambient temperature; Yield given;