Selektivnost Diels–Alderjeve reakcije na primeru substituiranih 2H-piran-2-onov: mikrovalovni ali klasični pogoji kot način za pospešitev aromatizacije ali cikloadicije

Kamin, Rebeka (author), Kranjc, Krištof (mentor)

V magistrskem delu sem raziskovala Diels–Alderjevo reakcijo 3-benzoilamino-6-(2-tienil)-2H-piran-2-ona z maleinanhidridom pod različnimi reakcijskimi pogoji. Pri reakciji pod refluksom je nastal biciklični dvojni adukt (substituiran biciklo[2.2.2]okt-7-en). Reakcija pod mikrovalovnim obsevanjem je vodila do nastanka istega bicikličnega dvojnega adukta ter neznanega stranskega produkta, za katerega sem kasneje ugotovila, da gre za aromatski produkt (derivat izobenzofurana) in našla ustrezne mikrovalovne pogoje za sintezo le-tega kot edinega produkta. Optimizirala sem tudi reakcijske pogoje za sintezo aromatskega produkta pod klasičnimi pogoji z dodatkom aktivnega oglja. Mikrovalovna sinteza aromatskega produkta je bila bistveno hitrejša, okolju prijaznejša, produkt je bil čistejši in izkoristek višji v primerjavi s klasično sintezo. Tekom eksperimentalnega dela sem opazila razpadanje bicikličnega dvojnega adukta na TLC silikagelnih ploščicah ter razpad nekoliko podrobneje raziskala. Silikagel bi potencialno lahko bil uporaben kot katalizator za hidrolizo anhidridnih obročev bicikličnih dvojnih aduktov.

• Language: Slovenian
• Keywords: 2H-piran-2-oni, Diels–Alderjeva cikloadicija, biciklo[2.2.2]okt-7-en, izobenzofuran, mikrovalovna sinteza, aromatizacija z aktivnim ogljem, hidroliza na silikagelu
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2022
• PID: 20.500.12556/RUL-134827
• COBISS.SI-ID: 96369923
• Publication date in RUL: 03.02.2022

Secondary language

• Language: English
• Title: Selectivity of Diels–Alder reaction in the case of substituted 2H-pyran-2-ones: microwave vs. conventional conditions as means for achieving aromatization or cycloaddition

Abstract

In present work I investigated the Diels–Alder reaction of 3-benzoylamino-6-(2-thienyl)-2H-pyran-2-one with maleic anhydride under different reaction conditions. Reaction under reflux conditions yielded bicyclic double adduct (substituted bicyclo[2.2.2]oct-7-ene). Microwave irradiation led to formation of the same bicyclic double adduct and an unknown by-product, which I later identified as aromatic product (isobenzofuran derivative) and found appropriate microwave conditions for its formation as the only product. I also optimized reaction conditions for synthesis of aromatic product under conventional conditions with addition of activated charcoal. Microwave synthesis of aromatic product was much faster, environmentally friendly, product was cleaner and yield was higher compared to conventional synthesis. During research I also noticed and further investigated degradation process of bicyclic double adducts on TLC silicagel plates. Silicagel could be potentially used as catalyst for hydrolysis of anhydride moiety in bicyclic double adducts.

• Keywords: 2H-pyran-2-ones, Diels–Alder cycloaddition, bicyclo[2.2.2]oct-7-ene, isobenzofuran, microwave synthesis, aromatization with activated charcoal, hydrolysis on silicagel