Efficient and selective oxidative deprotection of tetrahydropyranyl ethers, ethylene acetals and ketals with silver and sodium bromates in the presence of aluminum chloride

Primary and secondary tetrahydropyranyl (THP) ethers are efficiently transf ormed to their carbonyl compounds with AgBrO3 and NaBrO3/AlCl3. Ethylene ac etals and ketals are transformed to their carboxylic acids and ketones resp ectively with AgBrO3/AlCl3 in refluxing acetonitrile. AgBrO3/AlCl3 is also able to transform ethylene acetals to aldehydes in refluxing carbon tetrach loride in high yields. In refluxing acetonitrile, ethylene acetals and keta ls are transformed to aldehydes and ketones with NaBrO3/AlCl3 We have also found that tetrahydropyranyl ethers are oxidized selectively in the presenc e of ethylene acetals and ketals with these reagents.