title: Facile synthesis of cleistetroside-2, a partially acetylated oligorhamnoside from Cleistopholis glauca and patens.
abstract: A tetrasaccharide, dodecanyl 4-O-acetyl-alpha-l-rhamnopyranosyl-(1-->3)-2,4-di-O-acetyl-alpha-l-rhamnopyranosyl-(1-->3)-4-O-acetyl-alpha-l-rhamnopyranosyl-(1-->4)-alpha-l-rhamnopyranoside (cleistetroside-2), was synthesized via '2+2' convergent strategy. Sequential regioselective 3-O-glycosylation of isopropyl 1-thio-alpha-l-rhamnopyranoside (4) with 4-O-acetyl-2,3-O-isopropylidene-alpha-l-rhamnopyranosyl trichloroacetimidate (8), and isopropyl 4-O-acetyl-2,3-O-isopropylidene-alpha-l-rhamnopyranosyl-(1-->3)-2,4-di-O-acetyl-alpha-l-1-thio-rhamnopyranoside (10) with dodecanyl 4-O-acetyl-alpha-l-rhamnopyranosyl-(1-->4)-2,3-O-isopropylidene-alpha-l-rhamnopyranoside (12), greatly facilitate the target availability.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Lijian
authors.initials: L
authors.lastname: Cheng
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Du
mesh_terms: D000107:Acetylation; D029061:Annonaceae / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000138:chemical synthesis; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors; D006031:Glycosylation; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D012210:Rhamnose / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D009844:Oligosaccharides; D006026:Glycoside Hydrolases; D012210:Rhamnose