Synthesis of spiroisoxazolidinyl-benzoisothiazolines by 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes with nitrones.

The spiroisoxazolidinyl-benzoisothiazoline derivatives were synthesized through a highly diastereoselective 1,3-dipolar cycloaddition of benzoisothiazole-2,2-dioxide-3-ylidenes with nitrones. The regiochemistry of cycloaddition was assigned on the 1 H NMR chemical shift of methane-H in 3 and 5 . The relative stereochemistry of cycloadducts was determined from the single-crystal X-ray crystallography. [ABSTRACT FROM AUTHOR]