Expanding the Scope of an Electrophilic Aromatic Substitution Discovery Experiment Including Hydride and Methyl Shifts

• Mallory V. Savakinas ^[1] ; Olivia M. Frey ^[1] ; Nicholas A. Piro ^[1] ; Ian J. Rhile ^[1] ; Christian S. Hamann ^[1]
  1. [1] Albright College

     Albright College

     City of Reading, Estados Unidos

     
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 98, Nº 12, 2021, págs. 3999-4008
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Friedel–Crafts alkylation reactions using a curated set of alcohols provide students with the opportunity to combine the study of electrophilic aromatic substitution with carbocation rearrangements. In this experiment students may be presented with up to nine alcohols that yield six products, all synthesized under identical reaction conditions. They distinguish their products using a range of instrumental methods including infrared, 1H NMR, and 13C NMR spectroscopies, and mass spectrometry. Additional characterization is provided by the determination of melting point/mixed-melting point and gas chromatographic retention time. Students work in teams to assign structures to their individual reaction products; providing nine starting materials ensures minimal duplicates in a given laboratory section. As students interpret their data, some discover that a carbocation rearrangement occurred, resulting in isolation of only one product despite starting from a pair of isomeric reagents. This laboratory provides students with the opportunity to engage in a range of laboratory and problem-solving skills, and thus is designed to be performed toward the end of a two-semester organic chemistry sequence.