Synthesis of 7 alpha-hydroxy derivatives of regulatory oxysterols

7 alpha-Hydroxy derivatives of oxysterols are of considerable interest because of their possible involvement in regulation of cholesterol metabolism This paper describes stereoselective syntheses and complete characterization of the 7 alpha-hydroxy derivatives of four key oxysterols: 25-hydroxycholesterol, 27-hydroxycholesterol, 24(S)-hydroxycholesterol, and 24(S),25-epoxycholesterol. (C) 2000 Elsevier Science Inc. All rights reserved.