1: 1.) LDA / 1.) hexane, THF, -70 deg C, 1.5 h, 2.) hexane, THF, from -70 deg C to RT 2: 55 percent / P2O5, MeSO3H / 1 h / Ambient temperature 3: 90 percent / pyridine hydrochloride / 0.5 h / 210 °C 4: 68 percent / K2CO3 / acetone; dimethylformamide / 18 h / Heating 5: 1.) BuLi / 1.) THF, -70 deg C, 1 h, 2.) THF, RT, 18 h 6: conc. HCl / ethanol / 1 h / Heating View Scheme

1: 1.) LDA / 1.) hexane, THF, -70 deg C, 1.5 h, 2.) hexane, THF, from -70 deg C to RT 2: 55 percent / P2O5, MeSO3H / 1 h / Ambient temperature 3: 90 percent / pyridine hydrochloride / 0.5 h / 210 °C 4: 68 percent / K2CO3 / acetone; dimethylformamide / 18 h / Heating 5: 1.) BuLi / 1.) THF, -70 deg C, 1 h, 2.) THF, RT, 18 h 6: conc. HCl / ethanol / 1 h / Heating View Scheme

1: 1.) LDA / 1.) hexane, THF, -70 deg C, 1.5 h, 2.) hexane, THF, from -70 deg C to RT 2: 55 percent / P2O5, MeSO3H / 1 h / Ambient temperature 3: 90 percent / pyridine hydrochloride / 0.5 h / 210 °C 4: 93 percent / K2CO3 / acetone / 3 h / Heating 5: 1.) BuLi / 1.) THF, -70 deg C, 1 h, 2.) THF, RT, 18 h 6: conc. HCl / ethanol / 1 h / Heating 7: 1.) OsO4, 2.) H2S / 1.) THF, RT, 18 h View Scheme