Stereoselective synthesis and biological activity of novel spiro-oxazinanone-C-glycosides

The stereoselective synthesis of novel spiro-oxazinanone nucleosides 9 and 10 has been achieved by microwave assisted 1,3-dipolar cycloaddition of exo-glucal (1) and nitrones (2), and followed by reduction, stereospecific recyclization, and catalytic deprotection. The structures of the spironucleosides were determined according to the 1H NMR, 13C NMR, 2D NMR, MS, and X-ray analyses, and the biological activities of the title compounds against glycosidases (α-amylase, α-glucosidase, and β-glucosidase) and cytotoxicity were also evaluated.