Intramolecular cycloaddition of nitrones in total synthesis of natural products

Covering 2015 to 2024Cycloaddition of nitrones with alkenes forms isoxazolidines, which are five-membered heterocycles containing nitrogen and oxygen atoms. This transformation functionalizes alkenes by forming C-C and C-O bonds. The N-O bond in the resultant isoxazolidines is easily cleaved. Additionally, when the cycloaddition is carried out intramolecularly, the regioselectivity of the reaction is influenced by the tether connecting the nitrone and alkene and can differ from the selectivity governed by frontier molecular orbital interaction. These features make the intramolecular cycloaddition of nitrones attractive in the synthesis of complex molecules. In this review, we discuss the intramolecular cycloaddition of nitrones used in the total synthesis of natural products.