title: N,N-acetals as N-acyliminium ion precursors: synthesis and absolute stereochemistry of epiquinamide.
abstract: A stereoselective synthesis of (+)-epiquinamide is presented in combination with determination of the absolute configuration of the natural product. Key steps in the sequence involved chemoenzymatic formation of an enantiomerically pure cyanohydrin, reductive cyclization to the corresponding cyclic N,N-acetal, and subsequent conversion into a suitable N-acyliminium ion precursor to enable construction of the second ring.
authors.affiliation: Radboud University Nijmegen, Institute for Molecules and Materials, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands.
authors.forename: Marloes A
authors.initials: MA
authors.lastname: Wijdeven
authors.forename: Roel
authors.initials: R
authors.lastname: Wijtmans
authors.forename: Rutger J F
authors.initials: RJ
authors.lastname: van den Berg
authors.forename: Wim
authors.initials: W
authors.lastname: Noorduin
authors.forename: Hans E
authors.initials: HE
authors.lastname: Schoemaker
authors.forename: Theo
authors.initials: T
authors.lastname: Sonke
authors.forename: Floris L
authors.initials: FL
authors.lastname: van Delft
authors.forename: Richard H
authors.initials: RH
authors.lastname: Blaauw
authors.forename: Richard W
authors.initials: RW
authors.lastname: Fitch
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Spande
authors.forename: John W
authors.initials: JW
authors.lastname: Daly
authors.forename: Floris P J T
authors.initials: FP
authors.lastname: Rutjes
mesh_terms: D000080:Acetals / Q000737:chemistry*; D000818:Animals; D001001:Anura; D001688:Biological Products / Q000138:chemical synthesis / Q000737:chemistry; D002412:Cations / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D011807:Quinolizines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D000080:Acetals; D001688:Biological Products; D002412:Cations; D007097:Imines; D011807:Quinolizines; C481035:epiquinamide