1,6-Cyclization Reactions of Selected Aldohexopyranoses via Their 1-O-Tosyl Derivatives

Abstract 2,3,4,6-Tetra-O-acetyl-d-gluco-, d-galacto- and d-mannopyranoses were tosylated with p-tolenesulfonyl chloride to afford their 1-O-tosyl derivatives which were cyclized “in situ” in a methanolic solution of sodium methoxide. 1,6-Cyclization products were obtained only with d-glucose and d-galactose derivatives. Cyclization of derivatives of d-glucose i.e. 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl chloride, 3,4,6-tri-O-acetyl-1,2-anhydro-α-d-glucopyranose (Brigl's anhydride) and 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide enabled the estimation of the influence of configuration at C-1 and C-2 on the course of cyclization. All product mixtures were separated by capillary gas chromatography (CGC) and their components were identified by coinjection with standards.