Methyl naphthoates, hydrolysis

Secalin. Secalin has been isolated from the stems of unripe rye.46,68 Schlubach and Bandmann69 studied its structure. The great difficulty they encountered in obtaining the polysaccharide and its acetate in homogeneous form made the determination of physical properties uncertain. However, by hydrolysis of the methyl derivative, they obtained, after separation by means of the /3-naphthoates, tetramethyl-, trimethyl-, and dimethyl-D-fructoses in the proportions of 1 2 1. The trimethyl-D-fructose was identified as 1,3,4-trimethyl-D-fructofura-nose by its melting point and specific rotation. 

Studies using the 1,8-naphthalene and 4,5-phenanthrene templates have been made (Bowden and Last, 1970, 1973a). The rates of alkaline hydrolysis of the methyl 8-formyl-1-naphthoate [23] and 4-formylphenanthrene-4-carboxylate [24] are very fast and have dramatic enhancements over... 

It is apparent that steric bulk and stereochemical control of mechanism operates in the alkaline hydrolysis of methyl 8-acyl-1-naphthoates. The proximity and favourable orientation of the carbonyl group at the 8-position facilitates intramolecular catalysis from this group. However, the formation of the tetrahedral intermediate at the 8-acyl carbonyl group has distinct... 

Relatively small retardations of the rate of the base catalyzed hydrolysis of methyl-1-naphthoate by sodium dodecylsulfate (NaLS) and hexadecyltrimethylammonium bromide (CTAB) in 50 wt percent dioxane-water have been observed. These effects were attributed to micelle formation in this solvent system since plots of In where 2 and are the second order rate constants in the presence and absence of the organic salts, vs. the concentration of the salts were non-linear... 

None of the products formed in the reactions described above is considered to significantly change the reaction rates and product distributions by acting as a catalyst. However, Siskin et al. [106] reported that in the hydrolysis of methyl 1-naphthoate at 343 °C naphthalene was predominantly formed because the potential for autocatalysis arises. They concluded that decarboxylation of naphthoic acid, the main product at a lower temperature of 250 °C, led to the formation of naphthalene at 343 °C the reaction is catalyzed by the generated carbonic acid. In the hydrolysis of typical p-keto esters, ethylacetoacetate was completely converted to acetone, eAanol, and CO2 within 30 min at 250 °C. Under the same conditions, r-butyl acetate degraded into a bright red, insoluble mixture of unidentifled products resulting from polymerization of isobutylene [107]. 

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