title: A hypervalent iodine-mediated spirocyclization of 2-(4-hydroxybenzamido)acrylates--unexpected formation of δ-spirolactones.
abstract: On the way towards a new total synthesis of (S)-arogenate, a novel aryl-λ(3)-iodane-mediated oxidative spirocyclization of para-substituted phenol derivatives has been discovered. Starting from easy accessible 2-(4-hydroxybenzamido)acrylates we could construct spirocyclic lactams in up to 52% yield. Under alternative reaction conditions the same precursors underwent an unexpected oxidative spirocyclization yielding a novel δ-spirolactone in up to 70% yield.
authors.affiliation: Eberhard Karls University, Institute of Organic Chemistry, Auf der Morgenstelle 18, Tuebingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Hempel
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Weckenmann
authors.forename: C
authors.initials: C
authors.lastname: Maichle-Moessmer
authors.forename: Boris J
authors.initials: BJ
authors.lastname: Nachtsheim
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D003500:Cyclization; D007455:Iodine / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D000179:Acrylates; D007783:Lactones; D013141:Spiro Compounds; D007455:Iodine