Synthesis of spiropyrrolidinyl-benzoisothiazoline derivatives by 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylide

Abstract The new spirocyclic compounds, spiropyrrolidinyl-benzoisothiazoline derivatives were synthesized by the 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes and azomethine ylide. The stereochemistry of 1,3-dipolar cycloaddition as well as the stereochemistry of Knoevenagel condensation of benzoisothiazole-2,2-dioxide with aldehydes were studied.