1: CH2Cl2 / 2 h / 20 °C 2: thionyl chloride / 1 h / 25 °C 3: tetrahydrofuran / 2 h / 20 °C 4: 88 percent / 4.5 N aq. HCl / 12 h / Heating 5: 1.) acetyl chloride / 1.) 0 deg C, 0.25 h, 2.) reflux, 4 h 6: N-bromosuccinimide, dibenzoyl peroxide / CCl4 / 3 h / Heating 7: 1.) sodium methoxide / 1.) DMF, 25 deg C, 0.25 h, 2.) DMF, 40 deg C, 4 h 8: 56 percent / manganese dioxide / CH2Cl2 / 40 h / 25 °C 9: 40 percent / N-bromosuccinimide / CCl4 / 0.5 h / Irradiation 10: 58 percent / 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / tetrahydrofuran / 18 h / 25 °C 11: 88 percent / sodium borohydride / methanol / 0.5 h / 0 °C 12: 10percent aq. NaOH / ethanol / 14 h / Heating View Scheme