title: A selective and mild glycosylation method of natural phenolic alcohols.
abstract: Several bioactive natural p-hydroxyphenylalkyl β-D-glucopyranosides, such as vanillyl β-D-glucopyranoside, salidroside and isoconiferin, and their glycosyl analogues were prepared by a simple reaction sequence. The highly efficient synthetic approach was achieved by utilizing acetylated glycosyl bromides as well as aromatic moieties and mild glycosylation promoters. The aglycones, p-O-acetylated arylalkyl alcohols, were prepared by the reduction of the corresponding acetylated aldehydes or acids. Various stereoselective 1,2-trans-O-glycosylation methods were studied, including the DDQ-iodine or ZnO-ZnCl2 catalyst combination. Among them, ZnO-iodine has been identified as a new glycosylation promoter and successfully applied to the stereoselective glycoside synthesis. The final products were obtained by conventional Zemplén deacetylation.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia.
authors.forename: Mária
authors.initials: M
authors.lastname: Mastihubová
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia.
authors.forename: Monika
authors.initials: M
authors.lastname: Poláková
keywords: 1,2-trans-glycosylation; diastereoselectivity; mild promoters; natural products; p-hydroxyphenylalkyl glycosides