Synthesis of α-ketols by functionalization of captodative alkenes and divergent preparation of heterocycles and natural products

Abstract Captodative alkene 1-acetylvinyl p -nitrobenzenecarboxylate 1a was evaluated for its reactivity in Lewis acid-catalyzed Michael additions with functionalized benzene rings and heterocycles, leading to diverse conjugated addition adducts. The hydrolysis of the latter resulted in the desired functionalized α-ketols, including natural alkaloid actinopolymorphol B ( 24a ). The α-ketol core structure of these compounds was used as the building block for the synthesis of the natural alkaloid tanakine ( 25 ) and for the divergent construction of highly substituted heterocycles, such as 4-oxazolin-2-ones and butenolides, and their respective fused polycyclic derivatives.