Remarkable High-pressure Enhancement of Enantiopure Nitrone Cycloadditions to Glycals: General Access to (12)-Linked Aza-C-disaccharides

1,3-Dipolar cycloadditions of enantiopure hydroxylated nitrones to glycals are strongly accelerated under high pressure. Under 10 Kbar pressure the process gains generality and broad scope and allows a direct access, in good to excellent yields, to stereodifferentiated tricyclic isoxazolidines, key intermediates for the synthesis of a new class of (1®2)-linked pseudo aza-C-disaccharides.