water; sodium hydroxide in methanol T=20°C; 3.25 h; Cooling with ice;

1: With aluminum isopropoxide in toluene 7 h; Reflux; 2: With Sodium potassium tartrate in toluene T=20°C;

1.1: potassium tert-butylate / dimethyl sulfoxide / 4 h / 20 °C / Inert atmosphere 2.1: aluminum isopropoxide / toluene / 7 h / Reflux 2.2: 20 °C View Scheme

1.1: toluene-4-sulfonic acid; water / acetone / 3.5 h / Reflux 2.1: potassium tert-butylate / dimethyl sulfoxide / 4 h / 20 °C / Inert atmosphere 3.1: aluminum isopropoxide / toluene / 7 h / Reflux 3.2: 20 °C View Scheme

1.1: triethylamine / 1,3-bis-(diphenylphosphino)propane; palladium diacetate / N,N-dimethyl-formamide / 5 h / 20 °C 2.1: lithium aluminium tetrahydride / tetrahydrofuran / 3 h / Reflux 2.2: 5 °C View Scheme

1.1: sodium hydride / dimethyl sulfoxide; mineral oil / 0.75 h / 50 °C / Inert atmosphere 1.2: 16.75 h / 50 °C 2.1: toluene-4-sulfonic acid; water / acetone / 3.5 h / Reflux 3.1: potassium tert-butylate / dimethyl sulfoxide / 4 h / 20 °C / Inert atmosphere 4.1: aluminum isopropoxide / toluene / 7 h / Reflux 4.2: 20 °C View Scheme