1: Jones'reagent / acetone / 6 h 2: 92 percent / pyridinium bromide perbromide / tetrahydrofuran / 0.5 h 3: 90 percent / LiBr, Li2CO3 / dimethylformamide / 0.75 h / Heating 4: 1) ozone, 2) water / ethanol, 1) - 80 deg C, 4 h, 2a) 1 h, RT, 2b) 30 min, reflux View Scheme

1: Jones'reagent / acetone / 6 h 2: 92 percent / pyridinium bromide perbromide / tetrahydrofuran / 0.5 h 3: 90 percent / LiBr, Li2CO3 / dimethylformamide / 0.75 h / Heating 4: 1) ozone, 2) water / ethanol, 1) - 80 deg C, 4 h, 2a) 1 h, RT, 2b) 30 min, reflux 5: 90 percent / NaOH, AgNO3 / ethanol; H2O / 4 h View Scheme

chromium(VI) oxide; sodium acetate; pyridine hydrochloride in dichloromethane