IBX in an ionic liquid:: eco-friendly oxidation of 17α-methylandrostan-3β,17β-diol, an intermediate in the synthesis of anabolic oxandrolone

An easily available hypervalent iodine(V) reagent, 2-iodoxybenzoic acid (IBX) immobilized in the ionic liquid [bmim][Br] was found to be an efficient and eco-friendly protocol for the oxidation of 17alpha-methylandrostan-3beta,17beta-diol (1). At ambient temperature oxidation of 1 with lBX gave mestanolone (2) in good yield and with an increased stoichiometric amount of IBX, oxidation adjacent to the carbonyl functionality (alpha,beta-unsaturation) occurred to give dehydrogenated 17 beta-hydroxy- 17alpha-methyl-Delta'-and rosten-3-one (3) as the major product in a one-pot reaction, The product is easily obtained by extraction with diethyl ether and evaporation of the solvent. (C) 2004 Elsevier Ltd. All rights reserved.