Nitrone cycloadditions to isolevoglucosenone: ready access to a new class of directly linked (1-->3)-imino-C-disaccharides.

Straightforward access to a new class of d-gulo- and d-allo-derived directly linked (1-->3)-imino-C-disaccharides by means of cycloaddition reactions of enantiopure polyhydroxylated pyrroline N-oxides with isolevoglucosenone is reported. The cycloaddition reactions display a high level of double asymmetric induction, which allows a partial kinetic resolution of a racemic nitrone. [reaction: see text]