Synthesis of 3-arylpropenyl, 3-arylpropynyl and 3-arylpropyl 2-azetidinones as cholesterol absorption inhibitors: Application of the palladium-catalyzed arylation of alkenes and alkynes

A series of 3-(3/-arylpropenyl)-2-azetidinones 8a-8k and 3-(3'-arylpropynyl)-2-azetidinones 16m-16p were prepared by the palladium-catalyzed arylation of 3-(3'-propenyl)-2-azetidinone 7, or by arylation of 4-pentenoic acid, or via ethyl 4-pentynoate followed by 2-azetidinone ring construction. The unsaturated 2-azetidinones were transformed to their saturated analogs 9a-9p by catalytic hydrogenation. Azetidinones 8a-8k, 9a-9p, and 16m-16p were evaluated for their biological activity as cholesterol absorption inhibitors in hamsters. (C) 2000 Elsevier Science Ltd. All rights reserved.