The deamination of 1-aminohexan-2-ol and 1-(aminomethyl)pentyl β-D-galactopyranoside; a model study of the selective cleavage of the hydroxylysine-bound glycosyl residues of collagen

Abstract

The reaction of 1-aminohexan-2-ol with nitrous acid gave a mixture of hexan-2-one, hexane-1,2-diol, 5-butyl-N-nitroso-2-pentyloxazolidine and 2,5-dibutyl-2-methyl-N-nitroso-oxazolidine, the proportions of which varied with the reaction conditions. The absence of 1,2-epoxyhexane from the product mixture is in marked contrast to results recently reported for a related aminoalcohol. 1-(Aminomethyl)pentyl β-D-galactopyranoside was synthesized as a model compound for the O-glycosylhydroxylysine residues of collagen, by the Lewis acid-catalysed reaction of β-D-galactopyranose penta-acetate with 1-nitrohexan-2-ol followed by reduction and deacetylation. The nitrosation of 1-(aminomethyl)pentyl β-D-galactopyranoside at pH 3.0–3.5 gave, as major products (>90%), D-galactose and hexan-2-one. This reaction constitutes a model for the selective cleavage, under very mild conditions, of the hydroxylysine-bound glycosyl residues of collagen.