The preferred rotamer about the C5—C6 bond of D-galactopyranoses and the stereochemistry of dehydrogenation by D-galactose oxidase

Abstract

¹H nuclear magnetic resonance studies on D-galactopyranoses with chirally deuterated hydroxymethyl groups revealed that the preferred rotamer about the C₅—C₆ bond of the D-galactopyranoses was not tg but gt. Studies on the stereochemistry of dehydrogenation of D-galactose oxidase from Dactyliumdendroides with chirally pure deuterated methyl β-D-galactopyranosides showed that there were two mechanisms for the enzymatic reaction: an efficient pro-S hydrogen atom specific oxidation and a far less efficient non-specific or pro-R specific oxidation.