A new synthesis of alpha-arbutin via Lewis acid catalyzed selective glycosylation of tetra-O-benzyl-alpha-D-glucopyranosyl trichloroacetimidate with hydroquinone.
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.
Wang
Zhao-Xia
ZX
Laboratory for Advanced Materials, Institute of Fine Chemicals, East China University of Science and Technology, Shanghai, PR China.
Shi
Xiao-Xin
XX
Chen
Guo-Rong
GR
Ren
Zhi-Hua
ZH
Luo
Lei
L
Yan
Jing
J
D000081:Acetamides; D000143:Acids / Q000737:chemistry*; D001104:Arbutin / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D062845:Chloroacetates; D006031:Glycosylation; D006873:Hydroquinones / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D014238:Trichloroacetic Acid / Q000737:chemistry
D000081:Acetamides; D000143:Acids; D062845:Chloroacetates; D006873:Hydroquinones; D014238:Trichloroacetic Acid; D001104:Arbutin; C009528:trichloroacetamide; C031927:hydroquinone