Optically active α-hydroxy ketones 4 have been prepared in high enantioselectivity by the catalytic, enantioselective oxidation of easily available and stable (E)-enol phosphates 2 by (salen) Mn(III) complex.
The newsynthesis of chiral and sterically hindered 1,2-amino alcohols derivatives of 2-methyl-indane and 1,2,3,4-tethrahydrophenanthrene based on cyclic enol phosphates were investigated. The desired products were obtained using three step procedure: oxidation of accessible enol phosphates, transformation α-hydroxy ketones into corresponding oximes and finally reduction of the last one to 1,2-amino
The asymmetric oxidation of a variety of differently substituted, acyclic and cyclic enol phosphates using the Sharpless AD-reagents AD-mix-alpha and AD-mix-beta, and a fructose derived chiral ketone as a catalyst, afforded the corresponding alpha-hydroxy ketones in high enantioselectivity and good yield. The influence of steric and electronic factors of the substrates on the facial stereoselectivity in the reported oxidations was studied. (C) 2012 Elsevier Ltd. All rights reserved.