Reactions of 3-functionalized chromones with triacetic acid lactone

Synthesis of some o-Hidroksi Enaminone Derivatives and Cyclohexadiene by Tandem Oxidative-Reaction in Tetrachloro-1,4-benzoquinone (TCB) Medium

“…Yukardaki sonuçlara dayanarak, daha sonra, bir dizi deneyler ile yeni geliştirilen Tandem Oxidative-Reaksiyonu ile kinolin türevleri sentezlendi Şema 2 de makul bir mekanizma önerildi. Sonuç olarak, bir TCB reaktifini bu çalışmada ilk defa kullanarak tandem oksidatif halkalaşması oda sıcaklığı gibi ılımlı koşullar altında yöntem geliştirildi [17][18][19][20][21][22]. Bu çalışma ayrıca daha uygun ve uygulanabilir bir yöntem olarak azaksantonların sentezine yönelik yeni bir yöntem geliştirildi.…”

Synthesis and characterization of the novel heteroannulated chromeno[2,3‐d]pyrimidines and chromeno[2,3‐d][1,3]thiazolo[3,2‐a] pyrimidines

“…1 (15), 136 (11), 120 (28), 92 (9),77 (16), 64 (7) A mixture of compound 8 (0.84 g, 2 mmol) and bromomalononitrile (0.29 g, 2 mmol), in DMF (10 ml) containing triethylamine (0.1 ml), was heated under reflux for 4 h. The dark-yellow crystals formed during heating were filtered, air dried and crystallized from DMF, yield (0.57 g, 59%), mp >300 C. IR (KBr, cm À1 ): 3423 (OH), 3332, 3256 (NH 2 ), 2225 (C ≡ N), 1682 (C=O pyrimidine ), 1656 (C=O γ-pyrone ), 1605 (C=N), 1572 (C=C). (23), 196 (10), 164 (8), 120 (13), 93 (11), 77 (14), 64 (8)…”

“…NMR, vibrational and electronic spectral analysis, as well as fluorescence, photochemical and DFT were investigated for a variety of substituted chromones [18][19][20][21][22]. Chromones bearing electron deficient functional groups (CHO, COOH, CN, CONH 2 , NO 2 ) at position-3 are very active building block for construction of a diversity of heterocyclic compounds [23][24][25][26]. Reactions of chromone-3-carboxaldehyde with bifunctional nucleophiles usually proceeds via condensation with the aldehyde function followed by γ-pyrone ring opening [27][28][29].…”

4-Hydroxy-2-pyrones: Synthesis, Natural Products, and Application

“…4-Hydroxy-2-pyrones are polyfunctional molecules that bear several electrophilic and nucleophilic centers that determine their application in organic synthesis. These heterocycles are attractive building blocks for the preparation of biologically important pyran structures, aromatics, polymers, azaheterocycles and acyclic structures via ring-opening transformations or pyran ring modifications [11][12][13][14][15][16][17][18][19][20][21]. Two molecules that receive the most attention are triacetic acid lactone (4-hydroxy-6-methyl-2H-pyran-2-one) [11] and 4-Hydroxy-2-pyrones are polyfunctional molecules that bear several electrophilic and nucleophilic centers that determine their application in organic synthesis.…”