1: 1.) KOH / 1.) DMSO, RT, 50 min, 2.) DMSO, RT 2 h 2: 1.) titanium tetrachloride, 2.) NaBH4 / 1.) CH2Cl2, 5 deg C, 0.5 h, 2.) CH2Cl2, MeOH, from 10 deg C to RT, 50 min 3: 18.9 g / H2SO4 / acetic acid / 2 h / 90 °C View Scheme

1: 1.) titanium tetrachloride, 2.) NaBH4 / 1.) CH2Cl2, 5 deg C, 0.5 h, 2.) CH2Cl2, MeOH, from 10 deg C to RT, 50 min 2: 18.9 g / H2SO4 / acetic acid / 2 h / 90 °C View Scheme

1: 18.9 g / H2SO4 / acetic acid / 2 h / 90 °C View Scheme

Yield given;