methanol; trimethylsilyl bromide T=20°C; 5 h; chemoselective reaction;

1.1: caesium carbonate; water / N,N-dimethyl-formamide / 2 h / 25 °C 2.1: toluene / 21 h / 100 - 110 °C 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 2 h / 50 °C 3.2: 0.5 h / 30 °C 4.1: hydrogenchloride; water / ethyl acetate / 1 h / 50 °C 5.1: sodium hydroxide; sodium tetrahydroborate / toluene; methanol / 0.5 h / 0 - 5 °C View Scheme

tetrabutyl ammonium fluoride in tetrahydrofuran Ambient temperature; Yields of byproduct given;

1.1: caesium carbonate; water / N,N-dimethyl-formamide / 2 h / 25 °C 2.1: toluene / 21 h / 100 - 110 °C 3.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 2 h / 50 °C 3.2: 0.5 h / 30 °C 4.1: hydrogenchloride; water / ethyl acetate / 1 h / 50 °C 5.1: sodium hydroxide; sodium tetrahydroborate / toluene; methanol / 0.5 h / 0 - 5 °C 6.1: 1,1-dimethylpropan-1-ol / 4 h / 65 - 75 °C / Resolution of racemate 7.1: potassium carbonate / toluene / 2 h / 50 °C View Scheme

1,8-diazabicyclo[5.4.0]undec-7-ene in water; acetonitrile T=60°C; 5 h;

copper(ll) bromide in acetonitrile T=20°C; 24 h;

2,3-dicyano-5,6-dichloro-p-benzoquinone in dichloromethane T=20°C; 24 h;

sulfated SnO2 in methanol T=20°C; 0.25 h;

copper(ll) bromide in acetonitrile T=20°C; 24 h;