sodium dithionite; sodium hydrogencarbonate in water; butan-1-ol 1 h; Heating / reflux; Product distribution / selectivity;

1: With hydrogenchloride in methanol; water T=20°C; pH=2 - 3; 2: With zinc in methanol; water pH=2 - ~ 6.5; 3 - 4 h; Product distribution / selectivity;