Treatment of isophorone with ethylene glycol and acid in toluenes afforded a 70: 30 mixture of ketals 8 and 9 in 88.5% yield. The ketals were readily separated by fractional distillation. Potassium permanganate oxidation of 8 in neutral medium gave 10 (72.5%). Dehydration of 10 was accomplished with methanesulfonyl chloride in refluxing pyridine to afforded enone 2 (63%).
