Bismuth(III) oxide perchlorate promoted rearrangement of epoxides to aldehydes and ketones

Aryl-substituted epoxides and aliphatic epoxides with a tertiary epoxide carbon undergo smooth rearrangement in the presence of 10-50 mol% bismuth(III) oxide perchlorate, BiOClO4.x H2O, to give carbonyl compounds. The rearrangement is regioselective with aryl substituted epoxides and a single carbonyl compound arising from cleavage of benzylic C-O bond is formed. BiOClO4 x H2O is relatively non-toxic, insensitive to air and inexpensive, making this catalyst an attractive alternative to more corrosive and toxic Lewis acids such as BF3 . Et2O or InCl3 currently used to effect epoxide rearrangements. (C) 2000 Elsevier Science Ltd. All rights reserved.