Spectroscopic and Computational Study of Hydrate vs. Hemiacetal Equilibria in 6,7-Epoxy-6,7-Dihydroquinoline-5,8-Dione

Öz

The hydration of carbonyl compounds and the formation of hemiacetals have been a topic of interest in organic chemistry. Hydration plays an important role in biological processes. Quinoline derivatives are also biologically active molecules with many applications. Equilibrium between 6,7-epoxy-6,7-dihydroquinoline-5,8-dione and its hydrate or hemiacetal form was investigated in aqueous and alcoholic solutions by NMR spectroscopy. Interestingly, no equilibrium was detected for the hydrocarbon counterpart. It was presumed that the existence of this equilibrium is highly dependent on the electronic structure of the molecule. To further understand the difference in reactivity to such systems, density functional theory (DFT) calculations were performed.

Anahtar Kelimeler

• Quinoline
• Quinone
• Hydration
• Hemiacetal

6,7-Epoksi-6,7-Dihidrokinolin-5,8-Dion'da Hidrat ve Hemiasetal Dengelerinin Spektroskopik ve Hesaplamalı Çalışması

Öz

Karbonil bileşiklerinin hidratasyonu ve hemiasetallerin oluşumu organik kimyada ilgi çekici bir konu olmuştur. Hidratasyon biyolojik işlemlerde özellikle de ilaç salınımında önemli bir rol oynar. Kinolin türevleri de birçok uygulama alanına sahiptir ve çok geniş spektrumda biyolojik olarak aktif moleküllerdir. Bir kinolin türevi olan 6,7-epoksi-6,7-dihidrokinolin-5,8-dion ile hidrat veya hemiasetal formu arasındaki denge, sulu ve alkollü çözeltilerde NMR spektroskopisi ile incelendi. İlginç bir şekilde, hidrokarbon analoğu için bir denge tespit edilmedi. Bu dengenin varlığının molekülün elektronik yapısına (azot atomu molekülün elektronik yapısını değiştirdiğinden) büyük ölçüde bağlı olduğu varsayıldı. Bu tür sistemlere karşı reaktiflikteki farkı daha iyi anlamak için yoğunluk fonksiyonel teorisi (DFT) hesaplamaları yapıldı.

Anahtar Kelimeler

• Kinolin
• Kinon
• Hidratasyon
• Hemiasetal

Kaynakça

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