Synthesis of pyran-4-ones from isoxazoles

Li, Chun‐Sing; Lacasse, Edith

doi:10.1016/s0040-4039(02)00567-1

Cited by 58 publications

(22 citation statements)

References 6 publications

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“…The combination of aromatic aldehydes and aliphatic alkenes gave the corresponding product with moderate yield (entries 9). 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Once the scope of the reaction was studied, a ring opening reaction [72][73][74][75][76][77][78][79] was carried out using 0.5 equivalents of Mo(CO) 6 and starting from the previously obtained isoxazoles 3 ( Table 4). The reaction took place with good yields when the substituents of the isoxazole were aromatic, independently of the electronic nature of the substituents in these rings (entries 1-3).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of 3,5-Disubstituted Isoxazoles and Isoxazolines in Deep Eutectic Solvents

Pérez

Ramón

2015

ACS Sustainable Chem. Eng.

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The synthesis of different 3,5-disubstituted isoxazoles and related isoxazolines using choline chloride:urea as deep eutectic solvent (DES) in a one-pot three step reaction has been accomplished successfully. The use of highly nucleophilic functionalized DES did not affect the process where highly electrophilic reagents or intermediates are involved. The presence of DES showed to be essential since the reaction in absence of this media did not proceed. The DES media could be reused up to five times without a detrimental effect on the yield of the reaction. To exemplify the synthetic potential of this methodology, the reaction was scaled up to gram scale without any noticeable problem. Finally, different isoxazoles were easily transformed into β-aminoenones.

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Section: Resultsmentioning

confidence: 99%

Synthesis of 3,5-Disubstituted Isoxazoles and Isoxazolines in Deep Eutectic Solvents

Pérez

Ramón

2015

ACS Sustainable Chem. Eng.

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“…Samarium diiodide [321] and transition-metal carbonyls [322,323], such as molybdenum hexacarbonyl in the presence of water, are also efficient reagents for the reductive cleavage of isoxazoles. Nitta et al have reported that 3-methyl-5-(2-oxoalkyl)isoxazoles 241 undergo a Mo(CO) 6 -induced reductive cleavage to give pyridin-4(1H)-ones 244 in a single step [322].…”

Section: Reactions With Nucleophilic Reagentsmentioning

confidence: 99%

“…Hydrolysis of 242 gives the enamino ketone 243, which cyclizes to the pyridin-4(1H)-ones 244. Li et al have shown that if the 2-oxoalkyl side-chain is at the 3-position of the isoxazole 245 the corresponding enamino ketone could be isolated after reduction with Mo(CO) 6 and could be cyclized to pyran-4-ones 246 under acidic conditions (Scheme 9.95) [323].…”

Section: Reactions With Nucleophilic Reagentsmentioning

confidence: 99%

Five‐Membered Heterocycles: 1,2‐Azoles. Part 2. Isoxazoles and Isothiazoles

Silva

Tomé

Melo

et al. 2011

Modern Heterocyclic Chemistry

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“…As an initial step, the reductive ring opening of the isoxazole ring with [Mo(CO) 6 ] [39] (0.5 equiv) was examined ( Table 7). As expected, the reaction proceeded successfully to produce the corresponding pyrimidine derivatives 8, containing an amino group, in nearly quantitative yield (Table 7, entries 1-4).…”

Section: Skeletal Transformation To Form Pyridoa C H T U N G T R E N mentioning

confidence: 99%

Synthesis of Tri‐ or Tetrasubstituted Pyrimidine Derivatives through the [5+1] Annulation of Enamidines with either N,N‐Dimethylformamide Dialkyl Acetals or Orthoesters and Their Application in a Ring Transformation of Pyrimidines to Pyrido[2,3‐d]pyrimidin‐5‐one Derivatives

Sasada

Aoki

Ikeda

et al. 2011

Chemistry A European J

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The [5+1] annulation of enamidines, which were prepared from functionalized silanes, organolithium compounds and two nitriles, with N,N-dimethylformamide dialkyl acetals as the C1 unit is described, leading to the synthesis of tri- and tetrasubstituted pyrimidine derivatives under catalyst- and solvent-free reaction conditions. Furthermore, the [5+1] annulation of enamidines by using orthoesters as the C1 unit is described, in which catalytic amounts of ZnBr(2) catalyze the annulation to produce polysubstituted pyrimidines under toluene or xylene reflux conditions. Moreover, the combination of a reductive ring-opening reaction with [Mo(CO)(6)] and a subsequent intramolecular cyclization with tBuOK effectively causes a skeletal transformation from the pyrimidines containing an isoxazolyl and an ethoxy substituent to form pyrido[2,3-d]pyrimidin-5-one frameworks in excellent yield.

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Synthesis of pyran-4-ones from isoxazoles

Cited by 58 publications

References 6 publications

Synthesis of 3,5-Disubstituted Isoxazoles and Isoxazolines in Deep Eutectic Solvents

Synthesis of 3,5-Disubstituted Isoxazoles and Isoxazolines in Deep Eutectic Solvents

Five‐Membered Heterocycles: 1,2‐Azoles. Part 2. Isoxazoles and Isothiazoles

Synthesis of Tri‐ or Tetrasubstituted Pyrimidine Derivatives through the [5+1] Annulation of Enamidines with either N,N‐Dimethylformamide Dialkyl Acetals or Orthoesters and Their Application in a Ring Transformation of Pyrimidines to Pyrido[2,3‐d]pyrimidin‐5‐one Derivatives

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