Enantioselective oxidation of vic-diols to optically active alpha-hydroxy ketones by a fructose-derived dioxirane

Optically active alpha-hydroxy ketones 3 have been prepared in moderate to good enantioselectivities through asymmetrization of meso-, and kinetic res olution of, racemic vic-diols 2 by enantioselective oxidation with the in s itu generated dioxirane from the fructose-derived ketone 1; the opposite se nse in the enantioselectivity of the two processes is explained in terms of the hydrogen-bonded transition-state structures for the concerted C-H oxyg en insertion. (C) 1998 Elsevier Science Ltd. All rights reserved.