The First Stereoselective Palladium-Catalyzed Cyclocarbonylation of β,γ-Substituted Allylic Alcohols
摘要:
beta,gamma-Substituted allylic alcohols react with CO in the presence of catalytic quantities of palladium acetate and 1,4-bis(diphenylphosphino)butane affording alpha,beta-substituted-gamma-butyrolactones in 42-85% isolated yields. The complete stereoselectivity observed in some cases is a significant feature of the lactonization reaction, with (E)-allylic alcohols affording trans-disubstituted lactones. Depending on the structure of the allylic alcohol used in the cyclocarbonylation reaction, the formation of the corresponding alkene or the beta,gamma-unsaturated carboxylic acid was observed as a side or the principal reaction.