A study of 13CH coupling constants in hexopyranoses

Abstract

Proton decoupled and undecoupled ¹³C n.m.r. spectra have been measured on a number of hexopyranoses. The direct coupling constants between the anomeric carbon atoms and protons {¹J[¹³C–H(1)]} were found to be ca. 160 in the β-anomers and ca. 170 Hz in the α-anomers; the difference of ca. 10 Hz between pairs of anomers was found in almost all cases. Chemical shifts and ¹J(¹³CH) values of the other carbon atoms in the pyranose rings were also measured.