Stereoselective synthesis and biological activity of cis azetidinones as cholesterol absorption inhibitors

The C-3 sidechain of azetidinones related to SCH 48461 was modified by introducing a hydroxyl group at the 1′ position. This led to the discovery of the cis azetidinone 2c, which had improved CAI activity. Compound 2c was prepared using a selective reduction and silane mediated debromination to control the relative stereochemistry of the three centers.