title: Direct synthesis of maradolipids and other trehalose 6-monoesters and 6,6'-diesters.
abstract: It was shown that reaction of trehalose with 1 equiv of a fatty acid in pyridine promoted by 1 equiv of the uronium-based coupling agent 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) at room temperature gives a good yield of the primary ester accompanied by small amounts of the diprimary ester using hexanoic, palmitic, and oleic acids as examples. Reactions using 2 equiv of the fatty acids gave the symmetrical diesters. The monoesters were reacted with different fatty acids to give nonsymmetric 6,6'-diesters in very good yields. Compounds synthesized include the most abundant component of the very complex maradolipid mixture, 6-O-(13-methyltetradecanoyl)-6'-O-oleoyltrehalose, and a component potentially present in this mixture, 6-O-(12-methyltetradecanoyl)-6'-O-oleoyltrehalose, a derivative of an ante fatty acid. The C5-C6 rotameric populations of 6-O-monoesters, symmetrical 6,6'-diesters, and 2,6,6'-triesters of fatty acids were calculated from the values of the H5-H6R and H5-H6S coupling constants and found to be similar to those found for glucose. The rotameric populations of the monosubstituted glucose residues in the 2,6,6'-triesters was altered considerably to favor the gt rotamer, presumably because of attraction between the 2- and 6'-fatty acid chains.
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3.
authors.forename: Nawal K
authors.initials: NK
authors.lastname: Paul
authors.forename: Jean-d'Amour K
authors.initials: JD
authors.lastname: Twibanire
authors.forename: T Bruce
authors.initials: TB
authors.lastname: Grindley
mesh_terms: D004952:Esters; D005227:Fatty Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D006017:Glycolipids / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D014199:Trehalose / Q000138:chemical synthesis* / Q000737:chemistry*; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D004952:Esters; D005227:Fatty Acids; D006017:Glycolipids; D011725:Pyridines; C568414:maradolipid; D014508:Urea; D014199:Trehalose; C023666:pyridine