Efficient synthesis of IPL576,092: a novel anti-asthma agent.

An enantioseletive synthesis of the novel anti-asthma agent IRL576,092 (2) is described. The synthetic route developed involves stereoselective 1,2-reduction of the enone carbonyl functionality of 6 and subsequent hydroboration as the key steps. Starting from the commercially available 5-androsten-3beta-ol-17-one 3, this approach affords IPL576,092 (2) in nine steps with overall yields of 25%, employing a limited number of chromatographic steps.