Synthesis of N-acetyllactosamine containing a D-[6-3H]galactopyranosyl group

A simple and convenient method for the introduction of radiolabel onto C-6' of N-acetyllactosamine is described. 1-N-Benzyl-3-O-beta-D-galactopyranosyl-D-arabinosylamine (1) was synthesized from 3-O-beta-D-galactopyranosyl-D-arabinose as described by Lee and Lee. Compound 1 was oxidized with D-galactose oxidase, and the product reduced with KB3H4 to introduce the label at C-6'. After dilution with unlabeled material, the N-benzyl-3-O-beta-D-[6-3H]galactopyranosyl-D-arabinosylamine was converted into 2-(benzylamino)-2-deoxy-4-O-D-[6-3H]galactopyranosyl-D-glucononitrile , which was subjected to simultaneous hydrogenolysis of the benzylamino and nitrile groups. N-Acetylation of the amino group as described by Alais and Veyrières afforded the crystalline title compound in 63% yield.