title: Asymmetric allylboration and ring closing alkene metathesis: a novel strategy for the synthesis of glycosphingolipids.
abstract: A novel strategy for the synthesis of D,L-glucosylceramide 1, a member of the glycosphingolipid class of natural products is described. Reagent-controlled asymmetric Brown allylboration gave excellent stereochemical control in the construction of adjacent stereocenters in the sphingoid base portion of the molecule. The trans-configured double bond was obtained as a single geometrical isomer by use of silicon-tethered olefin metathesis employing the Schrock carbene [(CF3)2MeCO]2Mo(=CHCMe2Ph)(=NC6H3-2,6-i-Pr2++ +) and in situ PhLi-induced ring-opening of the intermediate 5,6-dihydro-2H-1,2-oxasiline followed by protodesilylation with TBAF in DMSO. The synthesis was completed by long chain amide formation and global deprotection.
authors.affiliation: Department of Chemistry, Imperial College of Science, Technology and Medicine, London, UK. agmb@ic.ac.uk
authors.forename: A G
authors.initials: AG
authors.lastname: Barrett
authors.forename: J C
authors.initials: JC
authors.lastname: Beall
authors.forename: D C
authors.initials: DC
authors.lastname: Braddock
authors.forename: K
authors.initials: K
authors.lastname: Flack
authors.forename: V C
authors.initials: VC
authors.lastname: Gibson
authors.forename: M M
authors.initials: MM
authors.lastname: Salter
mesh_terms: D000475:Alkenes; D000498:Allyl Compounds; D001896:Boron Compounds; D005963:Glucosylceramides / Q000138:chemical synthesis; D006028:Glycosphingolipids / Q000138:chemical synthesis*; D010126:Ozone
chemical_list: D000475:Alkenes; D000498:Allyl Compounds; D001896:Boron Compounds; D005963:Glucosylceramides; D006028:Glycosphingolipids; D010126:Ozone