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

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

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