Syntheses of Disaccharide Isothiocyanates and Nucleoside Related Compounds

Abstract

Introduction of the isothiocyanate group into anomeric position of sugar moiety is effective for the syntheses of nucleoside (thymine, thiothymine, 5-azacytidine, and 5-azathiocytidine)and glycoproteins.
In this paper, we report here on convenient methods for the syntheses of modified nucleoside analogs utilizing disaccharide isothiocyanates [7 a-c]. The compounds of [7a-c] were reacted with acyl hydrazine to give thiocarboxamides (8), which afforded 1, 2, 4-triazole disaccharide [9 ] by treatment of Ac₂O-H₃PO₄ through a cyclodehydration reaction. Reactions of [7a-c] with 6-amino-1, 3-dimethyluracil gave disaccharide aminoisothiazolo [3, 4-d] pyrimi -[dines [11] in good yields. Treatments of [7 a-c] with T-amino-2'-deoxy-β-D-glucopyranose yielded diglycosylthioureas [12]. Reactions of [7 a-c] with chloroethylamine hydrochloride under basic conditions afforded disaccharide imidazoline-2-thiones [13] instead of N-glycosy12-c N'-chloroeth ylthioureas.