potassium tert-butylate 1.) CH2Cl2, tBuOH, -20 deg C, 30 min, 2.) -78 deg C to room temperature; room temperature, 8 h; Yield given. Multistep reaction. Yields of byproduct given;

potassium tert-butylate 1.) CH2Cl2, tBuOH, -20 deg C, 30 min, 2.) -78 deg C to room temperature; room temperature, 8 h; Yield given. Multistep reaction. Yields of byproduct given;