4663-28-9Relevant academic research and scientific papers
Polarographic behavior of ethyl esters of substituted diazoacetic and diazopyruvic acids
Zalesov,Posyagin,Vyaznikova
, p. 81 - 87 (2007/10/03)
Polarographic reduction of ethyl 5-aryl-2-diazo-3,5-dioxopentanoate and ethyl 6-aryl-3-diazo-2,4,6-trioxohexanoate in isopropanol-water solutions proceeds with three or four polarographic waves and yields, depending on the pH of the solution, pyridazine or pyrazolidine derivatives.
Thermal addition reaction of aroylketene with ethyl vinyl ether: Aromatic substituent effect on aroylketene reactivity
Toda, Jun,Saitoh, Toshiaki,Oyama, Taichi,Horiguchi, Yoshie,Sano, Takehiro
, p. 2457 - 2464 (2007/10/03)
A series of aroylketenes (2) generated by thermolysis of 5-aryl-2,3-dihydrofuran-2,3-diones (1) reacted with ethyl vinyl ether under a thermal condition to give 2,3-dihydro-4H-pyran-4-ones (3) and/or 4H-pyran-4-ones (4). In this reaction the electron withdrawing substituent (NO2, Cl) introduced into the aryl part enhanced the ketene reactivity (2b-e), while the electron donating one (OMe) did not affect its reactivity (2f-g) in a significant extent. The heteroaroylketenes (2h) and (2i) showed a fairly good reactivity.
Direct Observation of α-Oxo Ketenes Formed from 1,3-Dioxin-4-ones and the Enols of β-Keto Esters
Freiermuth, Beat,Wentrup, Curt
, p. 2286 - 2289 (2007/10/02)
The enol forms of β-keto esters thermolyze to alcohols and α-oxo ketenes, which are characterized by low-temperature IR spectroscopy and on warming regenerate the β-hydroxy-α,β-unsaturated esters. The matrix isolated s-Z and s-E forms of α-oxo ketenes are characterized and photochemically converted into other conformers or sites.Matrix photolysis of 2,2,6-trimethyl-1,3-dioxin-4-one gives the s-Z acetylketene initially. α-Oxo ketenes polymerize in the cold and dimerize only at elevated temperatures.
Synthesis of β-Ketocarboxamide Derivatives Using 2,2-Dimethyl-2H,4H-1,3-dioxin-4-ones
Sato, Masayuki,Ogasawara, Hiromichi,Komatsu, Sachiko,Kato, Tetsuzo
, p. 3848 - 3856 (2007/10/02)
Thermal reaction of 2,2-dimethyl-2H,4H-1,3-dioxin-4-ones (1) with amines was studied.Acylketenes 2, generated by heating of 1, reacted with anilines and benzylamine to give the corresponding β-ketocarboxamides (3,4, and 5) in good yields.The reaction of 1 with ammonia gave 3-amino-2-alkenamides (7), which were hydrolyzed to β-ketocarboxamides (6).The former products 7 were readily transformed to the 6-substituted 2-methyl-3H-pyrimidin-4-ones (9) via the 3-acetamido-2-alkenamides (8).Acylation of O-benzylhydroxylamine with 1 gave the β-ketohydroxamic acids 10.Debenzylation of 10 followed by cyclization gave rise to 5-alkyl-3-hydroxyisoxazoles (12).The reaction of 1 with amides gave the corresponding N-acetylated amides (13). Keywords --- 2H,4H-1,3-dioxin-4-one; thermal fragmentation; acylketene; acylation; carboxamide; hydroxamic acid; 3-hydroxyisoxazole; 3H-pyrimidin-4-one
