Efficient, stereoselective syntheses of 24(S),25-epoxycholesterol (I) have been developed starting from cholenic acid or stigmasterol, both featuring as the key step Sharpless asym. dihydroxylation of desmosterol acetate. This work permits prepn. of gram quantities of I for further evaluation as a natural regulator of cholesterol metab., specifically, e.g., as a ligand for the LXRα nuclear receptor.
- stereoselective synthesis