title: An efficient synthetic approach to polycyclic 2,5-dihydropyrroles from alpha-silyloxy ketones.
abstract: A three-step sequence to prepare polycyclic 2,5-dihydropyrroles from alpha-silyloxy ketones is presented. A Lewis acid-mediated ring fragmentation of cyclic gamma-silyloxy-beta-hydroxy-alpha-diazo esters provided tethered aldehyde ynoate intermediates which, when treated with amino acid silyl esters, underwent intramolecular azomethine ylide 1,3-dipolar cycloadditions. The 2,5-dihydropyrrole products were formed in good to excellent yield as single diastereomers.
authors.affiliation: Department of Chemistry, The University of Vermont, 82 University Place, Burlington, Vermont 05405, USA.
authors.forename: Cristian
authors.initials: C
authors.lastname: Draghici
authors.forename: Qiufeng
authors.initials: Q
authors.lastname: Huang
authors.forename: Matthias
authors.initials: M
authors.lastname: Brewer
mesh_terms: D003500:Cyclization; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D007659:Ketones; D011758:Pyrroles