Hydroxylysine containing glycoconjugate : an efficient synthesis of natural galactosylhydroxylysine (Gal-Hyl) and glucosylgalactosylhydroxylysine (Glu-Gal-Hyl) and of their 5-(S)-epimers

The paper reports the first chemical synthesis of alfa-D-glucopyranosyl-(1-2)-beta-D-galactopyranosyl-5-O-hydroxylysine, a biological marker of bone resorption and of its unnatural (5S)-epimer, starting from commercial sugars and amino acids. Moreover, the synthetic protocol set-up has resulted in a new procedure for the synthesis of the beta-D-galactopyranosyl-5-O-hydroxylysine and its unnatural (5S)-epimer.