Hexaacetyl D-mannose hydrazine is one type of important intermediates in saccharide chemistry. In this paper, its single crystal was obtained and furthermore, X-ray diffraction and quantum chemistry calculation were performed. It belongs to orthorhombic system, space group P212121, with a=16.267（3）, b=19.263（3）, c=7.1948（12）A, Mr=446.41, Dc=1.315 g/cm^3, V=2254.5（6）A^3 and Z=4. Meanwhile, the experimental results also provide information for designing a kind of molecular switch based on the mannose nitrogenous derivatives.
CAO RuiLIU Xiao-HongCHENG Chang-MeiWANG Ru-JiZHAO Yu-FenWANG Lai-Xi
A highly efficient method to get 3-and 6-modified mannose/ahrose derivatives for oligosaccharide synthesis is described. All the compounds were obtained exclusively with the combinations of 3-and/or 6-hydroxyl protection and/or activation（ including the configuration conversion of 3-carbon atom）.
LIU Xiao-hongXIE DangCHENG Chang-meiWANG Xia-yuGUO Xiao-qiangZHAO Yu-fen
