Pyromeconic acid

Pyrindole — see Pyrrolo[l,2-a]pyridine Pyrithyldlone as sedative, 1, 165 Pyromeconic acid from comenic acid, 3, 710 occurrence, 3, 692... [Pg.812]

Challenger and coworkers36 had hoped to obtain pyromeconic acid (XXVI) from pentoses (XXV) with A. oryzae, by analogy with the formation of kojic acid from hexoses. Instead, kojic acid was produced from L-arabinose and D-xylose. Corbellini and Gregorini,31 too, observed the... [Pg.154]

The fact that pyromeconic acid and allomaltol were only available with difficulty meant that direct synthesis of certain 3-hydroxy-4-pyridinones was not possible. However the demonstration that some of these compounds were accessible from maltol or ethylmaltol by functionalizing the position adjacent to the ring-oxygen by an aldol condensation and N-oxide intermediates led to the preparation of 2-(l -hydroxyalkyl) and 2-amido derivatives with usefully high affinities for Fe + (70). [Pg.174]

A theoretical evaluation of the aromaticity of the pyrones pyromeconic acid, maltol, and ethylmaltol along with their anions and cations was carried out at several levels (Hartree-Fock, SVWN, B3LYP, and B1LYP) using the 6-311++G(d,p) basis set <2005JP0250>. The relative aromaticity of these compounds was evaluated by harmonic oscillator model of aromaticity (HOMA), nucleus-independent chemical shifts (NICSs), and /6 indexes and decreases in the order cation > neutral molecule > anion. [Pg.347]

Studies on the tautomerism of heterocycles, including pyrans and derivatives, have been extensively reviewed <2006AHC(91)1>. Computational studies have been used to examine a number of 3-hydroxy-4-pyranones such as maltol 68, ethyl maltol 69, and pyromeconic acid 70, and it has been determined that the 3-hydroxy-4-oxo tautomer is the most stable <2003JMT(639)87>. [Pg.348]

SYNS 2-ETHYL-3-HYDROXYAH-PYRAN-4-ONE 2-ETHYL PYROMECONIC ACID 3-HYDROXY-2-ETHYL-4-PYRONE... [Pg.635]

SYNS CORPS PRALINE 3-HYDROXY-2-METHYL-4H-PYRAN-4-ONE 3-HYDROXY-2-METHYL-7-PYRONE 3-HYDROXY-2-METHYL-4-PYRONE LARIXIC ACID U3RIXINIC ACID 2-METHYL-3-HYDROXY-4-PYRONE 2-METHYL-3-OXY-7-PYRONE 2-METHYL PYROMECONIC ACID PALATONE TALMON VETOL... [Pg.856]

ETHYL PYROMECONIC ACID see EMA600 N-ETHYLPYRROLIDINONE see EPC700... [Pg.1685]

Ethyl pyromeconic acid 3-hydroxy-2-ethyl-4-pyrone Veltol Plus. [Pg.272]

Hydroxy-2-methyl-(l,4-pyran) 3-hydroxy-2-methyl-4-pyr-one larixinic acid 2-methyl-3-hydroxy-4-pyrone 2-methyl pyromeconic acid Palatone Veltol. [Pg.445]

The first successful synthesis of maltol started from pyromeconic acid, which itself was an expensive material, and gave maltol in low yields. Today, industrial production is carried out by fermentation (kojic acid produced by an Aspergillus fungus) combined with chemical synthesis [10,20]. The synthetic routes include oxidation of kojic acid and addition of formaldehyde. By substituting acetaldehyde for formaldehyde, ethyl maltol (Fig. 3.60) is produced [20]. [Pg.362]

The structures of several 3-hydroxy-4-pyranones, such as pyromeconic acid 152 (R1 = R2 = H), maltol 152 (R1 = Me R2 = H), ethylmaltol 152 (R1 = Et R2 = H) and kojic acid 152 (R1 = H R2 = CH2OH) were calculated using 6-311 + +G(d,p) basis set (03JST(639)87). The 3-hydroxy-4-oxo forms shown were found to be predominant in all cases with the second most stable tautomer being 2/7-3,4-dioxo form. [Pg.65]

Synonyms 2-Ethyl-3-hydroxy-4H-pyran-4-one 2-Ethyl pyromeconic acid 3-Hydroxy-2-ethyl-4-pyrone... [Pg.1758]

Ethyl pyromeconic acid. See Ethyl maltol Ethyl pyrophosphate, tetra-. See Tetraethyl pyrophosphate... [Pg.1774]

Synonyms 3-Hydroxy-2-methyl-4H-pyran-4-one 3-Hydroxy-2-methyl-4-pyrone 3-Hydroxy-2-methyl-y-pyrone Larixic acid Larixinic acid 2-Methyl-3-hydroxy-4-pyrone 2-Methyl-3-oxy-y-pyrone 2-Methyl pyromeconic acid Empirical CeHeOs Formula CH3CsH20(0)(0H)... [Pg.2483]

Methyl pyromeconic acid. See Maltol Methyl pyromucate. See Methyl 2-furoate 1-Methylpyrrolidine... [Pg.2683]

Torii S, Tanaka H, Anoda T, Simizu Y (1976) A convenient preparation of maltol, ethylmaltol and pyromeconic acid from 2-alkyl-6-methoxy-2H-pyran-3(6H)-ones. Chem Lett 5 495-498... [Pg.806]

Ichimoto, L Ueda, H. Tatsumi C. (1965) Studies on kojic acid and its related y-Pyrone compounds. Part VII. The alkylation of Kojic Acid and Pyromeconic Acid through their Mannich Base. Agric. Biol Chem., Vol.l(2), pp.94-98. [Pg.22]

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