1: 6-bromo-2,2-dimethyl-4H-1,3-benzodioxin With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 2 h; 2: N,N-dimethyl-formamide in tetrahydrofuran; hexane T=-78 - 20°C; Further stages.;

1.1: 95 percent / p-toluenesulfonic acid monohydrate; Na2SO4 / acetone / 72 h / 40 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 2 h / -78 °C 2.2: 94 percent / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

1.1: 89 percent / LiAlH4 / tetrahydrofuran / 3 h 2.1: 95 percent / p-toluenesulfonic acid monohydrate; Na2SO4 / acetone / 72 h / 40 °C 3.1: n-BuLi / tetrahydrofuran; hexane / 2 h / -78 °C 3.2: 94 percent / tetrahydrofuran; hexane / -78 - 20 °C View Scheme

toluene-4-sulfonic acid in acetone

1: water; calcium carbonate / tetrahydrofuran 2: toluene-4-sulfonic acid / acetone View Scheme

1: hydrogenchloride; sulfuric acid / water 2: water; calcium carbonate / tetrahydrofuran 3: toluene-4-sulfonic acid / acetone View Scheme

hydrogenchloride in water; acetonitrile Heating;