Synthesis of 24-functionalized oxysterols

The syntheses of (24S)-24,25-epoxycholesterol, (24S)-hydroxycholesterol, and 24-ketocholesterol are described. The compounds belong to oxysterols, which can be considered to be the modulators of cholesterol metabolism. The asymmetric hydroxylation of desmosterol acetate according to Sharpless was used as the key reaction in the stereoselective introduction of functionality in position 24.