aluminum isopropoxide in cyclohexane; toluene T=145 - 150°C; Oppenauer oxidation; 20 h;

sodium hydroxide in tetrahydrofuran T=20°C; 1 h;

methanol; copper dichloride in pyridine 0.5 h; Heating;

piperidine

boron tribromide in dichloromethane T=30°C;

hydrogenchloride in tetrahydrofuran 1 h;

1: K2CO3; tetrabutylammonium iodide / dimethylformamide / 72 h / 20 °C 2: 1.45 g / aq. HCl / tetrahydrofuran / 1 h View Scheme

1: Na2HPO4; m-chloroperbenzoic acid / CH2Cl2; CHCl3 / 1 h / 20 °C 2: 13.8 g / NaOH / methanol / 2 h 3: K2CO3; tetrabutylammonium iodide / dimethylformamide / 72 h / 20 °C 4: 1.45 g / aq. HCl / tetrahydrofuran / 1 h View Scheme

1.1: p-TsOH / toluene / 14 h / Heating 2.1: NaH / dimethylformamide / 0 °C 2.2: 19.5 g / dimethylformamide / 16 h / 20 °C 3.1: sec-BuLi / tetrahydrofuran / 2 h / -78 °C 3.2: 86 percent / tetrahydrofuran / 1 h / -78 - 0 °C 4.1: Na2HPO4; m-chloroperbenzoic acid / CH2Cl2; CHCl3 / 1 h / 20 °C 5.1: 13.8 g / NaOH / methanol / 2 h 6.1: K2CO3; tetrabutylammonium iodide / dimethylformamide / 72 h / 20 °C 7.1: 1.45 g / aq. HCl / tetrahydrofuran / 1 h View Scheme

1.1: NaH / dimethylformamide / 0 °C 1.2: 19.5 g / dimethylformamide / 16 h / 20 °C 2.1: sec-BuLi / tetrahydrofuran / 2 h / -78 °C 2.2: 86 percent / tetrahydrofuran / 1 h / -78 - 0 °C 3.1: Na2HPO4; m-chloroperbenzoic acid / CH2Cl2; CHCl3 / 1 h / 20 °C 4.1: 13.8 g / NaOH / methanol / 2 h 5.1: K2CO3; tetrabutylammonium iodide / dimethylformamide / 72 h / 20 °C 6.1: 1.45 g / aq. HCl / tetrahydrofuran / 1 h View Scheme