1: With sulfur dioxide in dichloromethane T=-40°C; 1 h; Photolysis; 2: With sodium tetrahydroborate; nickel dichloride in tetrahydrofuran; methanol T=0°C; 0.25 h;

1.) K 1.) toluene, 2h, 0 deg C, ultrasonic irradiation, 2.) RT, 30min; Yield given. Multistep reaction. Yields of byproduct given;

1.) K 1.) toluene, 2h, 0 deg C, ultrasonic irradiation, 2.) RT, 30min; Yield given. Multistep reaction. Yields of byproduct given;