Asymmetric synthesis of N-1-(heteroaryl)ethyl-N-hydroxyureas

The asymmetric synthesis of two 5-lipoxygenase inhibitors (R)-N-1-(benzofuran-2-yl)ethyl-AT-hydroxyurea, 99% ee, and (R)N-1-(benzo [b]thiophen-2-yl)ethyl-N-hydroxyurea, 95% ee, is described. The enantioselective reduction of 1-(benzofuran-2-yl)ethanone oxime O-benzyl ether and 1-(benzo[b]thiophen-2-yl)ethanone oxime O-benzyl ether with borane oxazaborolidine, generated from (1R,2S,3R,4S)-3-amino-1, 7,7-trimethylbicyclo [2.2.1]heptan-2-ol, was used for the formation of the stereogenic centres. (C) 2008 Elsevier Ltd. All rights reserved.