1: pyridine, CrO3 / CH2Cl2 2: 5percent AcOH 3: DIBAL-H 4: 92 percent / BuLi, Ph3CH, p-TsCl, LiCl / hexamethylphosphoric acid triamide; hexane; diethyl ether / Ambient temperature 5: 1.) EtMgBr; 2.) 5percent CH3COOH / 1.) THF, 24 h, r.t.; 2.) 0 deg C, THF/H2O 6: 80 percent / NaH / dimethylsulfoxide / 3 h / 60 °C 7: 98 percent / acetone, p-TsOH / Heating View Scheme

1: pyridine, CrO3 / CH2Cl2 2: 5percent AcOH 3: DIBAL-H 4: 92 percent / BuLi, Ph3CH, p-TsCl, LiCl / hexamethylphosphoric acid triamide; hexane; diethyl ether / Ambient temperature 5: 1.) EtMgBr; 2.) 5percent CH3COOH / 1.) THF, 24 h, r.t.; 2.) 0 deg C, THF/H2O View Scheme

pyridine; chromium(VI) oxide in dichloromethane