Structure of a 2,3,4-tri-O-acetyl-β-D-glucopyranosuronic acid derivative

Methyl { 1-[ ( 1 'R)1 '-methoxybutyl]-2,3,4-triO-acetyl-fl-D-glucopyranosid }uronate, ClsH2sOt 1, Mr =420.41 , orthorhombic, P212121, a = 8 . 6 0 4 ( 3 ) , b = 13.500 (2), c = 18.664 (4) A, V = 2167.9 A 3, z = 4, D x = 1.288 Mg m -3, 2(Mo Ks) = 0.71069 A, /~ = 0-10 mm -1, F(000) = 896, T = 298 K, R = 0.055 for 1592 observed reflections. The structure was investigated to determine the relative configuration, which could not be established unambiguously by NMR. The endocyclic acetal bond is longer than the exocyclic by