Conformational analysis of furanose rings with PSEUROT: parametrization for rings possessing the arabino, lyxo, ribo, and xylo stereochemistry and application to arabinofuranosides.
The solution conformation of a furanose ring can be assessed through PSEUROT analysis of three-bond (1)H-(1)H coupling constants ((3)J(HH)) of the ring hydrogens. For each coupling constant, PSEUROT requires two parameters, A and B, which are used to translate the H[bond]C[bond]C[bond]H dihedral angle predicted from the (3)J(HH) into an endocyclic torsion angle from which the identity of the conformers can be determined. In this paper, we have used density functional theory methods to generate a family of envelope conformers for methyl furanosides 1-8. From these structures, A and B were calculated for each H[bond]C[bond]C[bond]H fragment. In turn, the values of these parameters for the arabinofuranose ring were used in PSEUROT calculations to determine the conformers populated by monosaccharides 1 and 2 as well as the furanose rings in oligosaccharides 9-15. The results of these analyses are consistent with the low-energy conformers identified from previous computational and X-ray crystallographic studies of 1 and 2.
Houseknecht
Justin B
JB
Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
Altona
Cornelis
C
Hadad
Christopher M
CM
Lowary
Todd L
TL
D002625:Chemistry, Organic / Q000379:methods; D018360:Crystallography, X-Ray; D004187:Disaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D009005:Monosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D004187:Disaccharides; D005663:Furans; D009005:Monosaccharides