title: Thioglycosylation of 1,2-cis-glycosyl acetates: a long-standing overlooked issue in preparative carbohydrate chemistry.
abstract: 1,2-cis-Glycosyl acetates with the α-configuration were revealed to be very unreactive towards Lewis acid catalyzed thioglycosylations. Optimal and cost-effective conditions for enabling this direct conversion is absent in the literature. Our studies have shown that elevating the reaction temperature with a catalytic amount of BF(3)·OEt(2) was more effective than changing Lewis acids with higher acidities to accommodate the low reactivity of α-glycosyl acetates. The effect of impurities in stored BF(3)·OEt(2) on the reaction is also discussed.
authors.affiliation: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Ci
authors.initials: C
authors.lastname: Xu
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.forename: Xuechen
authors.initials: X
authors.lastname: Li
mesh_terms: D000085:Acetates / Q000138:chemical synthesis / Q000737:chemistry*; D002236:Carbohydrate Conformation; D005697:Galactosides / Q000138:chemical synthesis* / Q000737:chemistry; D005960:Glucosides / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D000085:Acetates; D005697:Galactosides; D005960:Glucosides; D013438:Sulfhydryl Compounds