title: 3-O-benzoyl-4,6;4',6'-di-O-benzylidene-2,2'-dideoxy,alpha,alpha-ribo- trehalose.
abstract: The low-temperature X-ray structure of an asymmetrically substituted derivative of alpha,alpha-trehalose, 3-O-benzoyl-4,6;4',6'-di-O-benzylidene-2,2'-dideoxy-alpha,alpha-ribo-tre halose (3-O-benzoyl-4,6-O-benzylidene-2-deoxy-alpha-D-ribo-hexopyranosyl 4,6-O-benzylidene-2-deoxy-alpha-D-ribo-hexopyranoside, C33H34O10), is reported. The hexopyranosyl rings and the 1,3-dioxane rings have normal 4C1 chair conformations, so that each half of the molecule has a double-chair conformation, resembling a trans-decalin ring system. Each benzylidene acetal group takes the form of the thermodynamically more stable (R)-diastereomer with its phenyl group attached to the 1,3-dioxane ring in an equatorial orientation. The conformations about the glycosidic linkages are stabilized by the anomeric effect and by an intramolecular hydrogen bond between the lone hydroxy group and the glycosidic O atom.
authors.affiliation: Organisch-chemisches Institut, Universität Zürich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Linden
authors.forename: C K
authors.initials: CK
authors.lastname: Lee
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D014199:Trehalose / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: C094665:3-O-benzoyl-4,6,4',6'-di-O-benzylidene-2,2'-dideoxyribotrehalose; D014199:Trehalose