title: Synthesis of Leonosides E and F derived from Leonurus japonicas Houtt.
abstract: Leonosides E and F, two natural phenylethanoid glycosides derived from Leonurus japonicas Houtt, which bear different trisaccharide moieties-one linear and one branched, were totally synthesized via a direct transglycosylation strategy. After trisaccharyl trichloroacetimidates 3 and 4 were prepared as glycosyl donors, they were coupled with the homovanillyl aglycon via silver triflate-promoted transglycosylation to successfully furnish the fully protected glycosides, which were globally deprotected to afford the target molecules in 6.77% and 10.08% overall yields for the longest linear synthetic sequence starting from 6 and 14.
authors.affiliation: National Glycoengineering Research Center, Shandong University, Jinan 250010, PR China. Electronic address: guofenggu@sdu.edu.cn.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Gu
authors.forename: Yisheng
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhongwu
authors.initials: Z
authors.lastname: Guo
mesh_terms: D002240:Carbohydrate Sequence; D060326:Chemistry Techniques, Synthetic; D006139:Guaiacol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D031332:Leonurus / Q000737:chemistry*; D008969:Molecular Sequence Data; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: C572242:2-(3-methoxy-4-hydroxyphenyl)ethanol-O-arabinopyranosyl-(1-2)-rhamnopyranosyl-(1-3)-glucopyranoside; C572243:2-(3-methoxyl-4-hydroxyphenyl)ethanol-O-rhamnopyranosyl-(1-3) (glucopyranosyl-(1-6))-glucopyranoside; D014312:Trisaccharides; D006139:Guaiacol
keywords: Carbohydrate; Leonoside E; Leonoside F; Phenylethanoid glycoside; Total synthesis; Transglycosylation