potassium hydroxide; zinc in 1,4-dioxane; water Heating;

hydrogenchloride; water in ethyl acetate T=70°C; 12 h; Inert atmosphere;

1.1: tris(4-methylphenyl)-phosphine; trimethylsilyl-methylmagnesium chloride; cobalt(II) dibromide / tetrahydrofuran / 0.5 h / |Inert atmosphere; |Schlenk technique; |Cooling with ice 1.2: 12 h / 40 °C / |Inert atmosphere; |Schlenk technique 2.1: water; hydrogenchloride / ethyl acetate / 0.5 h / 20 °C / |Inert atmosphere 3.1: water; hydrogenchloride / ethyl acetate / 12 h / 70 °C / |Inert atmosphere View Scheme

1.) diethyl ether, THF, -60 deg C 2.) Zn, KOH, pyridine, H2O, MeOH, reflux, 2.5 h 3.) ZnCl2, acetic acid, 30 min 4.) HI, hypophosphoric acid, 30 min; Yield given. Multistep reaction;