3-Sphere Approach on 9-O-(10,11-di-O-benzyl-12,14-O-benzylidene-α-D-galactopyranosyl)-1-butyl-2,3-O-isopropylidene-1,4-dideoxy-1,4-imino-1-<I>N</I>-dehydro-L-ribitol

Abstract

The conformation of 9-O-(10,11-di-O-benzyl-12,14-O-benzylidene-α-D-galactopyranosyl)-1-butyl-2,3-Oisopropylidene-1,4-dideoxy-1,4-imino-1-N-dehydro-L-ribitol 1, phase angles of the pseudorotation of five (C 3 ) and six (C 1 4 ) membered rings, was analyzed with dihedral angles θ HnHn+1 [deg] calculated only from vicinal coupling constants 3 J HH [Hz] with 3-Sphere approach and VISION molecular models. The dimension space around the six and five membered ring are established based on hypersphere equations results from calculation of the dihedral angles from carbon chemical shift. Higher biological activity was observed to date at iminocyclitols having dihedral or vicinal angles calculated in 2D. Tetrahedral angles in close relationships with dihedral angles are calculated from carbon and / or proton chemical shift with manifold equations, conic and rectangle geometries. Equations for calculation of the tetrahedral angles φ Cn [deg] only from vicinal coupling constant 3 J HnHn+1 [deg] or from chemical shift δ Cn [ppm] are analyzed for five and established for six membered ring, resulting general rules for calculation of tetrahedral angles. Conic as manifold in case of six membered ring enable calculation of dihedral angle θ HnHn+1 [deg] from tetrahedral angle φ Cn [deg] starting with tetrahedral angle on unit, and in case of five membered ring based on opposite relationship between dihedral and tetrahedral (sin versus tan function), unit start with dihedral angles. Rectangle as manifold enable calculation for both the tetrahedral angle from dihedral angle starting with dihedral angle on unit, for six membered ring using two or three units with three sets angles and in case of five membered ring only one unit with seven set angles. The bond distances l CnCn+1 [A 0 ] of five and six membered ring are calculated from 3-Sphere-dihedral angles θ HnHn+1 [deg].