potassium tert-butylate 1.) ether, 0 deg C, 1 h, 2.) ether, THF, RT, 30 min; Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;

potassium hydrogensulfate T=300°C;

1: HCl 2: KHSO4 / 300 °C View Scheme