The Paterno-Buchi Reaction on Furan Derivatives

The Paterno-Buchi reaction on furan derivatives is reviewed. The photochemical reaction of furan derivatives in the reaction with carbonyl compounds gives the corresponding monoadduct with high regio- and stereoselectivity. When the reaction is carried out in benzene, a large amount of the diadduct can be obtained. The exo stereoselectivity at C-6 was explained assuming the presence of a secondary orbital effect on spin orbit coupling. Regio- and stereoselectivity of the reaction of carbonyl compounds with 2,3-dihydrofuran is described. Applications of the reaction to the synthesis of 2- and 3-furylmethanol derivatives is reported. The synthesis of asteltoxin, avenaciolide, and oxetanocin is also reported. Asymmetric reactions on chiral glyoxylate is reported. The low diastereoselectivity of the reaction with chiral ketones and aldehydes is discussed. Finally, the high diastereoselectivity observed in the reaction with 2-furylmethanol derivatives is reported.