Oxysterols: 27-hydroxycholesterol and its radiolabeled analog

We describe a convenient and stereoselective route to the synthesis of 27-h ydroxycholesterol. Also its radiolabeled analog, 22, 23 di [H-3]-27-hydroxy cholesterol with high specific radioactivity (55 Ci/mmol) was synthesized b y this method. Julia condensation of steroidal 22-sulfone with aldehyde, le d to the addition of the 23-27 carbon side chain building block to the ster oid backbone. Formed in this reaction beta-hydroxysulfone moiety was reduce d by sodium amalgam generate 22-23 unsaturated bond. Further reduction eith er by hydrogen or tritium furnished substrates for the synthesis of title c ompounds. (C) 2000 Elsevier Science Inc. All rights reserved.