1: 71 percent / H2 / Pd-CaCO3 2: 65 percent / Et3SiH, CF3CO2H / benzene; CH2Cl2 3: 80 percent / BBr3 / CH2Cl2 / 0 °C View Scheme

1: With palladium 10 on activated carbon; hydrogen in benzene T=0°C; 12 h; 2: With triethylsilane; trifluoroacetic acid in benzene T=20°C; 13 h; stereoselective reaction;

triethylsilane; trifluoroacetic acid T=25°C; 4 h;

1: With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 1 h; Inert atmosphere; 2: With acetic acid in tetrahydrofuran T=-78 - 20°C;

hydrogenchloride in acetic acid T=20°C; Dehydration; Rerrangement; 3 h;

chromium(VI) oxide; Celite in diethyl ether; dichloromethane T=25°C; 12 h;

1.1: 77 percent / I2; PDC / CH2Cl2 / 46 h / 25 °C 2.1: 49 percent / BH3*PhNEt2 / diphenyl((S)-pyrrolidin-2-yl)methanol; B(OMe)3 / tetrahydrofuran / 1.5 h / 25 °C 3.1: 91 percent / DMAP; pyridine / diethyl ether / 2 h / 25 °C 4.1: CuCN*2LiCl / tetrahydrofuran / 0.5 h / 0 °C 4.2: 66 percent / tetrahydrofuran / 25 °C 5.1: n-BuLi / tetrahydrofuran; pentane / 0.5 h / -78 °C 5.2: B(OMe)3 / tetrahydrofuran; pentane / 24 h / -78 - 25 °C 5.3: 45 percent / NaBO3*4H2O / tetrahydrofuran; pentane / 24 h / 25 °C 6.1: p-TsOH / benzene / 12 h / 25 °C 7.1: TBAF / tetrahydrofuran / 16 h / 25 °C 8.1: 17 mg / Celite; CrO3 / diethyl ether; CH2Cl2 / 12 h / 25 °C View Scheme

1.1: 49 percent / BH3*PhNEt2 / diphenyl((S)-pyrrolidin-2-yl)methanol; B(OMe)3 / tetrahydrofuran / 1.5 h / 25 °C 2.1: 91 percent / DMAP; pyridine / diethyl ether / 2 h / 25 °C 3.1: CuCN*2LiCl / tetrahydrofuran / 0.5 h / 0 °C 3.2: 66 percent / tetrahydrofuran / 25 °C 4.1: n-BuLi / tetrahydrofuran; pentane / 0.5 h / -78 °C 4.2: B(OMe)3 / tetrahydrofuran; pentane / 24 h / -78 - 25 °C 4.3: 45 percent / NaBO3*4H2O / tetrahydrofuran; pentane / 24 h / 25 °C 5.1: p-TsOH / benzene / 12 h / 25 °C 6.1: TBAF / tetrahydrofuran / 16 h / 25 °C 7.1: 17 mg / Celite; CrO3 / diethyl ether; CH2Cl2 / 12 h / 25 °C View Scheme

1.1: imidazole / dimethylformamide / 12 h / 25 °C 2.1: I2; PDC / CH2Cl2 / 48 h / 25 °C 3.1: BH3*PhNEt2 / diphenyl((S)-pyrrolidin-2-yl)methanol; B(OMe)3 / tetrahydrofuran / 1.5 h / 25 °C 4.1: 91 percent / DMAP; pyridine / diethyl ether / 2 h / 25 °C 5.1: CuCN*2LiCl / tetrahydrofuran / 0.5 h / 0 °C 5.2: 66 percent / tetrahydrofuran / 25 °C 6.1: n-BuLi / tetrahydrofuran; pentane / 0.5 h / -78 °C 6.2: B(OMe)3 / tetrahydrofuran; pentane / 24 h / -78 - 25 °C 6.3: 45 percent / NaBO3*4H2O / tetrahydrofuran; pentane / 24 h / 25 °C 7.1: p-TsOH / benzene / 12 h / 25 °C 8.1: TBAF / tetrahydrofuran / 16 h / 25 °C 9.1: 17 mg / Celite; CrO3 / diethyl ether; CH2Cl2 / 12 h / 25 °C View Scheme

1.1: BH3*PhNEt2 / diphenyl((S)-pyrrolidin-2-yl)methanol; B(OMe)3 / tetrahydrofuran / 1.5 h / 25 °C 2.1: 91 percent / DMAP; pyridine / diethyl ether / 2 h / 25 °C 3.1: CuCN*2LiCl / tetrahydrofuran / 0.5 h / 0 °C 3.2: 66 percent / tetrahydrofuran / 25 °C 4.1: n-BuLi / tetrahydrofuran; pentane / 0.5 h / -78 °C 4.2: B(OMe)3 / tetrahydrofuran; pentane / 24 h / -78 - 25 °C 4.3: 45 percent / NaBO3*4H2O / tetrahydrofuran; pentane / 24 h / 25 °C 5.1: p-TsOH / benzene / 12 h / 25 °C 6.1: TBAF / tetrahydrofuran / 16 h / 25 °C 7.1: 17 mg / Celite; CrO3 / diethyl ether; CH2Cl2 / 12 h / 25 °C View Scheme