1,3-Dipolar Cycloaddition of Difluoro(methylene)cyclopropanes with Nitrones: Efficient Synthesis of 3,3-Difluorinated Tetrahydropyridinols

Difluoro-substituted spirocyclopropaneisoxazolidines were formed by 1,3-dipolar cycloaddition of difluoro(methylene)cyclopropanes (F 2 MCPs) with nitrones in high yields. The [3+2]-cycloaddition reactions exhibited good regioselectivity and high stereoselectivity. The cycloadducts could rearrange further to form highly substituted 3,3-difluorinated tetrahydropyridinols.