Transmission of polar effects. Part 18. Ionisation and esterification with diazodiphenylmethane of a series of 3-(8-substituted-1-naphthyl)propiolic and (E)-3-(8-substituted-1-naphthyl)acrylic acids and the alkaline hydrolysis of the methyl esters of the former series

1990 ◽  
pp. 1197 ◽  
Author(s):  
Keith Bowden ◽  
Mahmood Hojatti
Keyword(s):  
Alkaline Hydrolysis ◽  
Methyl Esters ◽  
Acrylic Acids ◽  
Hydrolysis Of ◽  
Substituted 1

THE TRANSMISSION OF POLAR EFFECTS: PART III. THE KINETICS OF THE ACID-CATALYZED ESTERIFICATION OF 3-SUBSTITUTED ACRYLIC ACIDS AND THE ALKALINE HYDROLYSIS OF THE METHYL ESTERS

1966 ◽  
Vol 44 (6) ◽  
pp. 661-669 ◽  
Author(s):  
Keith Bowden
Keyword(s):  
Alkaline Hydrolysis ◽  
Methyl Esters ◽  
Rate Coefficients ◽  
Steric Effects ◽  
Trans Isomers ◽  
Electrostatic Effect ◽  
Acid Catalyzed ◽  
Acrylic Acids ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate coefficients for the acid-catalyzed esterification in methanol at 35.0° of fourteen 3-substituted acrylic acids have been determined. Rate coefficients have also been determined for the alkaline hydrolysis in 70% v/v dioxin–water at 18.8° of 13 methyl esters and the carbonyl-stretching frequencies of the esters have been examined. The effect of trans-substitution is assessed by use of the Hammett equation. In the alkaline hydrolysis, the transmission of polar effects is approximately 1.9 that of the meta- and para-substituted benzoates. An analysis of the steric effects in the cis-isomers in both reactions shows that the steric effects of the halogeno-substituents in the two reactions differ and an explanation is offered. The application of the Taft–Ingold equation to ortho-substituted benzoates is criticized. The carbonyl-stretching frequencies of the cis-halogeno-esters exhibit a shift of +8 cm−1 compared with the trans-isomers; this shift is attributed to an electrostatic effect.

Synthesis and properties of 5-styryl-2-furancarboxylic acids

1981 ◽  
Vol 46 (11) ◽  
pp. 2724-2728 ◽  
Author(s):  
Viera Knoppová ◽  
Anton Beňo ◽  
Jaroslav Kováč
Keyword(s):  
Ir Spectra ◽  
Transmission Coefficient ◽  
Alkaline Hydrolysis ◽  
Methyl Esters ◽  
Uv And Ir Spectra ◽  
Substituted Benzaldehydes ◽  
Hydrolysis Of

5-(4-X-Styryl)-2-furancarboxylic acids (X = H, Br, NO2, COOCH3, (CH3)2N) were prepared by oxidation of the appropriate 5-(4-X-styryl)-2-furaldehydes, or alternatively by alkaline hydrolysis of the corresponding methyl esters. The latter were obtained by reacting the 4-substituted benzaldehydes with 5-methoxycarbonylfuryltriphenylphosphonium chloride. The UV and IR spectra of products are commented. The apparent pK values of the synthesized acids were employed for calculation of the transmission coefficient π' through the benzene-furan system bridged by a -CH=CH- group.

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