Formal Methylene Insertion into the C–H Bond of α-Carbonyl Aldonitrones with Dimethylsulfoxonium Methylide

金沢大学理工学研究域物質化学系A methylene group was introduced into the C–H bond of α-carbonyl aldonitrones by reaction with dimethylsulfoxonium methylide, producing one-carbon homologated C-methyl ketonitrones. This formal methylene insertion was applied to one-pot synthesis of quaternary C3-methyl isoxazolidines via successive 1,3-dipolar cycloaddition with alkenes bearing an electron withdrawing group