The crystal structures of 3-O-benzyl-1, 2-O-isopropylidene-5-O-methane�lfonyl-6-O- tri�enyl�thyl-α-D-gluco�ran�e and its azide displacement product

Abstract

The effect of different leaving groups on the substitution versus elimination outcomes with C-5 D-glucose derivatives was investigated. The stereochemical configurations of 3-O-benzyl-1,2-O-iso­propyl­idene-5-O-methane­sulfonyl-6-O-tri­phenyl­methyl-α-D-gluco­furan­ose, C36H38O8S (3) [systematic name: 1-[(3aR,5R,6S,6aR)-6-benz­yloxy-2,2-di­methyl­tetra­hydro­furo[2,3-d][1,3]dioxol-5-yl)-2-(trit­yloxy)ethyl methane­sulfonate], a stable inter­mediate, and 5-azido-3-O-benzyl-5-de­oxy-1,2-O-iso­propyl­idene-6-O-tri­phenyl­methyl-β-L-ido­furan­ose, C35H35N3O5 (4) [systematic name: (3aR,5S,6S,6aR)-5-[1-azido-2-(trit­yloxy)eth­yl]-6-benz­yloxy-2,2-di­methyl­tetra­hydro­furo[2,3-d][1,3]dioxole], a substitution product, were examined and the inversion of configuration for the azido group on C-5 in 4 was confirmed. The absolute structures of the mol­ecules in the crystals of both compounds were confirmed by resonant scattering. In the crystal of 3, neighbouring mol­ecules are linked by C—H...O hydrogen bonds, forming chains along the b-axis direction. The chains are linked by C—H...π inter­actions, forming layers parallel to the ab plane. In the crystal of 4, mol­ecules are also linked by C—H...O hydrogen bonds, forming this time helices along the a-axis direction. The helices are linked by a number of C—H...π inter­actions, forming a supra­molecular framework.