A new synthesis of alpha-arbutin via Lewis acid catalyzed selective glycosylation of tetra-O-benzyl-alpha-D-glucopyranosyl trichloroacetimidate with hydroquinone

摘要

alpha-Arbutin has huge application potentials in the cosmetic industry,as its inhibitory effect on human tyrosinase is stronger than that of its naturally occurring anomer arbutin(4-hydroxyphenyl beta-D-glucopyranoside).Enzymatic synthesis was preferred for alpha-arbutin previously,and now a new chemical synthesis is reported.The reaction of tetra-O-benzyl-alpha-D-glucopyranosyl trichloroacetimidate,as glycosyl donor,with hydroquinone was initiated by catalytic amounts of trimethylsilyl trifluoromethanesulfonate(TMSOTf),resulting in 4-hydroxyphenyl 2,3,4,6-tetra-O-benzyl-alpha-D-glucopyranoside with high stereoselectivity and yield,and then to alpha-arbutin quantitatively after deprotection.