Isovanillic acid

The synthesis of 5,7,4 -trihydroxy-3 -methoxyflavone was performed in an analogous way, substituting 0-benzylvanillic anhydride and sodium 0-benzylvanillate in place of the substances of the isovanillic acid series. 

Benzoic acid, 3-hydroxy-4-methoxy- isovanillic acid 2042, 3308, 3394, 3712, 3793, 3797 ... 

Benzoic acid, 3-hydroxy- isovanillic acid 45. Phenol, 2-methoxy- ... 

Steck, W. and S.H. Wender Chlorogenic and neochloro-genic adds in dgarette smoke Tob. Sd. 9 (1965) 54—55. Steck, W, C.H. Yang, and S.H. Wender Identification of salicylic and isovanillic acids in cigarette smoke Chem. Ind. (1965)560-561. 

The correctness of the assumption that the parent vinyl carboxylic acid of LXIII must have the structure LXIV was shown by the oxidation of LXIV to 4,5,5 -tricarboxy-2,2 -dimethoxydiphenyl ether (LXV) and comparison with the compound synthesized by the Ullmann condensation of 4-iodo-5-methoxyphthalic acid with isovanillic acid (69) or by the condensation of 3-methyl-4-acetyl-6-methoxyphenol with 3-bromoanisic acid followed by oxidation (69). The natural LXV and the synthetic compound were identical in all respects. When the three degradation products, LXIV, LIX and trimethylamine, were pieced together the structure LXVI for bebeerine was arrived at, the positions of the phenolic groups being assigned arbitrarily. 

Because methylene blue is a cationic dye, it would be expected to have activity as a Lewis acid. The correlation with methylene blue was weak but showed the expected trend, with increased methylene blue binding being negatively correlated to increased Phloroglucinol and isovanillic acid were the only laccase substrates that increased the ATp of the fiber. All substrates other than resorcinol, 4-hydroxyphenylacetic acid, 1,2,3-trihydroxybenzene, and 1,2,4-... 

Aryl-aldehyde dehydrogenase was purified from Neurospora crassa to remove a dehydrogenase that reduces vanillin to vanillyl alcohol 23). Vanillic acid, isovanillic acid, and PCA were extracted from a fermentation broth with ethyl acetate. Reprecipitation of the isolated products increased the vanillic acid PCA ratio from 1 2 to 2.5 1 (mol/mol). Incubation of the resulting mixture with aryl aldehyde dehydrogenase, NADP, and ATP for 7 h at 30 C resulted in a 92% reduction of vanillic acid to vanillin but only a 33% reduction of PCA to protocatechualdehyde. Vanillin was extracted from the reaction with CH2CI2, affording a product with 10 mol % isovanillin as the only detected contaminant. Based on the concentration of vanillic acid in the fermentation broth, reduction of vanillic acid through purification of vanillin proceeded in 66% overall yield. 

Cryst. M.p. 177-82 —> anhydride. Sd. EtOH. Heat —> ca-amiDopiperonahcarbosylio anhydride + isovanillic acid. 

Amino-1-methyl-n-butyric Acid, q.v. Isovanillic Acid (Prcdocatechuic acid 4-mefhyl ether, 3-hydroxy-4-methoxybenzoic acid, 3-hydroxy-anisic aoid)... 

It had been previously established that quinic acid readily forms a lactone, called quinide. Quinide was shown to have a 7-lactone structure by conversion of the trimethyl ether to 3-hydroxy-4-methoxybenzoic acid (isovanillic acid). At the same time, this reaction established that the hydroxyl at carbon 6 and the carboxyl must be on the same side of the ring. Since the hydroxyl derivative obtained through the Grignard reaction consumes one mole of lead tetraacetate and from the results of the Curtius degradation, it follows that carbon 2 must have both a carboxyl and hydroxyl attached. Furthermore, since the resultant ketone cannot form an osazone, carbons 1 and 3 must be free of hydroxyl groups. By elimination, therefore, the remaining two hydroxyls must be at carbons 4 and 5. Finally, these must... 

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