1: 66 percent / sodium ethoxide / ethanol / 0.5 h / Heating 2: 89 percent / m-chloroperbenzoic acid / CHCl3 / 3.5 h / 0 °C 3: 1.) aluminium trichloride; 2.) chromium trioxide, 98percent sulphuric acid / 1.) methylene dichloride, 5 deg C, 3 min; 2.) acetone, 20 deg C, 4 h View Scheme

1: 66 percent / sodium ethoxide / ethanol / 0.5 h / Heating 2: 89 percent / m-chloroperbenzoic acid / CHCl3 / 3.5 h / 0 °C 3: 1.) aluminium trichloride; 2.) chromium trioxide, 98percent sulphuric acid / 1.) methylene dichloride, 5 deg C, 3 min; 2.) acetone, 20 deg C, 4 h 4: 1.) thionyl chloride; 2.) dry ammonia / 1.) 50 deg C, 24 h.; 2.) 5 deg C, 20 min 5: 77 percent / lithium hydride / dimethylformamide / 2.5 h / 140 °C View Scheme