title: A bidirectional approach to the synthesis of polypropionates: synthesis of C1-C13 fragment of zincophorin and related isomers.
abstract: The structure-activity study of a bioactive natural product containing polypropionate subunits requires that its stereoisomers also be evaluated. Therefore, a general approach to synthesize these motifs is necessary. We describe herein the synthesis of the C1-C13 polypropionate subunit of zincophorin and isomers thereof using a two-reaction sequence: an aldol reaction using a mixture of tetrasubstituted enoxysilanes and a hydrogen-transfer reaction, both under Lewis acid control. Selection of the appropriate Lewis acid dictates the stereochemical outcome of these reactions. From a tactical standpoint, this study shows how a polypropionate sequence can be read and constructed in two directions, either the east-west or the west-east approaches. The choice of the optimal route is influenced by the number of complexation sites that can interfere in the aldol step under bidentate Lewis acid control.
authors.affiliation: Bio-organic Chemistry Laboratory, Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, Québec, Canada H2W 1R7.
authors.forename: Philippe
authors.initials: P
authors.lastname: Mochirian
authors.forename: François
authors.initials: F
authors.lastname: Godin
authors.forename: Ioannis
authors.initials: I
authors.lastname: Katsoulis
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fontaine
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Brazeau
authors.forename: Yvan
authors.initials: Y
authors.lastname: Guindon
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D006859:Hydrogen / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D011422:Propionates / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D011108:Polymers; D011422:Propionates; D006859:Hydrogen; C116609:3-hydroxybutanal; C043279:zincophorin