Formation of 3,6-anhydro-D-glucofuranosides in an acid-cata- lysed alcoholysis of partially tosylated D-glucose derivatives

摘要

Partial esterification of D-glucose with 2 moles of tosyl chloride in pyridine at 14 deg. C gave 2,6-di-O-p-toluenesulphony-D-glucopyranose (1) as the main reaction product (55/100) and 6-O-p-toluenesulphonyl-D-glucopyranose (2) as the minor product (33/100). The reaction of D-glucono-1,5-lactone (3) with 5 moles of tosyl chloride in pyridine at -10 deg. C gave the corresponding 2, 6-di-O-tosyl derivative 4(62/100), which was further treated with sodium borohydride in DMSO, at room temperature, to afford compound 1 in 95/100 yield.