1: 2.) 3 M aq. NaOH / 1.) ether, room temp., 3 h, 2.) room temp., 6 h 2: 52 percent / pyridinium dichromate / dimethylformamide / 6 h / Ambient temperature 3: 87 percent / Al2O3 (Woelm neutral for TLC) / 48 h / Ambient temperature View Scheme