2004

CarbohydratesU 0500 Stereocontrolled Glycosidations Using a Heterogeneous Solid Acid, Sulfated Zir-

conia, for the Direct Syntheses of α- and β-Manno- and 2-Deoxyglucopyranosides. — The glycosidation of manno- (I) and deoxyglucopyranosyl fluorides (XI) with var-ious alcohols (II), (V) and (VII) is readily activated by the heterogeneous solid acid

/ZrO2. The stereoselectivity is strongly influenced by the solvent and the amount of solid acid used, and conditions can be identified for highly diastereoselective α- or β-glycosidation reactions. — (TOSHIMA*, K.; NAGAI, H.; KASUMI, K.-I.; KAWAHARA, K.; MATSUMURA, S.; Tetrahedron 60 (2004) 25, 5331-5339; Dep. Appl. Chem., Fac. Sci. Technol., Keio Univ., Kohoku, Yokohama 223, Japan; Eng.) — Mischke

40- 193

SO2-4

2004