title: Synthesis and elaboration of functionalised carbohydrate-derived spiroketals.
abstract: The scope of a stereoselective three-step approach for the synthesis of sugar derived spiroketals is presented. The methodology consists of Grignard addition of vinyl- or allylmagnesium bromide to a carbohydrate lactone, followed by K-10 clay mediated glycosidation with a terminal alkenol and subsequent ring-closing metathesis of the resulting diene. The generality of this procedure is demonstrated by the synthesis of various pyranose- and furanose-derived spiroketals, as well as more advanced tricyclic spiroketal derivatives. It is shown that functionalisation of the double bond in the resulting spiroketals leads to fused polycyclic ethers.
authors.affiliation: TNO Prins Maurits Laboratory, AA Rijswijk, The Netherlands.
authors.forename: Peter A V
authors.initials: PA
authors.lastname: van Hooft
authors.forename: Farid
authors.initials: F
authors.lastname: El Oualid
authors.forename: Herman S
authors.initials: HS
authors.lastname: Overkleeft
authors.forename: Gijsbert A
authors.initials: GA
authors.lastname: van der Marel
authors.forename: Jacques H
authors.initials: JH
authors.lastname: van Boom
authors.forename: Michiel A
authors.initials: MA
authors.lastname: Leeuwenburgh
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry; D008968:Molecular Conformation; D013141:Spiro Compounds / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D002241:Carbohydrates; D007783:Lactones; D013141:Spiro Compounds