The stereochemistry of the addition of glycerol to D-galactal, catalyzed by beta-D-galactosidase.
On incubation with beta-D-galactosidase, D-galactal-2-d (1) plus glycerol yielded 1-deoxyglycerol-1-yl 2-deoxy-beta-D-lyxo-hexopyranoside-2(S)-d. By 1H-n.m.r. analysis, it was shown that the hydrogen atom introduced on C-2 is trans-related to the aglycon moiety. In contrast to this stereospecific, enzyme-catalyzed addition, the reaction of phenol with peracetylated 1, catalyzed by p-toluenesulfonic acid, which yields phenyl 3,4,6-tri-O-acetyl-2-deoxy-alpha-D-lyxo-hexopyranoside-2-d, was shown to entail both a trans and a cis addition.
D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology; D005696:Galactosidases / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D006601:Hexoses / Q000378:metabolism*; D013237:Stereoisomerism; D001616:beta-Galactosidase / Q000378:metabolism*
D006601:Hexoses; D005696:Galactosidases; D001616:beta-Galactosidase; D005990:Glycerol