potassium tert-butylate in tetrahydrofuran T=-78°C; 18 h; Yield given. Yields of byproduct given;

1: 1.) Mg / 1.) diethyl ether, 15 min, reflux, 2.) 10 min 2: 3 N chromic acid / acetone / 1 h / 45 °C 3: potassium tert-butoxide / tetrahydrofuran / 18 h / -78 °C View Scheme

1: 1.) Mg / 1.) diethyl ether, 15 min, reflux, 2.) 10 min 2: 3 N chromic acid / acetone / 1 h / 45 °C 3: potassium tert-butoxide / tetrahydrofuran / 18 h / -78 °C View Scheme