1: Et3N / CH2Cl2 / 1 h / Ambient temperature 2: DBU / toluene / 1 h / 100 °C 3: 1.) O3, 2.) Me2S / 1.) MeOH, -78 deg C, 2.) -78 deg C to room temp. 4: Jones reagent / acetone / 2 h / 0 °C View Scheme

1: Et3N / CH2Cl2 / 1 h / Ambient temperature 2: DBU / toluene / 1 h / 100 °C 3: 1.) O3, 2.) Me2S / 1.) MeOH, -78 deg C, 2.) -78 deg C to room temp. 4: Jones reagent / acetone / 2 h / 0 °C View Scheme

1: Et3N / CH2Cl2 / 1 h / Ambient temperature 2: DBU / toluene / 1 h / 100 °C 3: 1.) O3, 2.) Me2S / 1.) MeOH, -78 deg C, 2.) -78 deg C to room temp. View Scheme