Isocrotonic acid

The acid prepared as above is the Irans isomer isocrotonic acid is produced by special methods. 

Iso-crotonsaure, /. isocrotonic acid, -cumarin, n. isocoumarin, isocumarin. -cyansaure, /. isocyanic acid, -cyanursaure, /. isocyanuric add. 

Isobutyl octadecanoate, i75 Isobutyraldehyde, m3 89 Isobutyric acid, m402 Isocapronitrile, m361 Isocinchomeronic acid, p269 Isocrotonic acid, b483 Isocumene, p225... 

Isocitric acid, in citric acid cycle, 6 633 Isocontour surfaces, discrete, 10 340 Isocorrosion diagrams, 23 784 Isocratic chromatography, 3 827 Isocrotonic acid, physical properties,... 

Isocrotonic acid, 53, 123 (+)-ISOPINOCAMPHEOL, 52, 59 Isopropenyl acetate, acylation of, 52, 1... 

Sometimes the prefix iso is used to signify the less stable isomer as in isocrotonic acid which is cis and it is less stable. Similarly the prefix alio is also used to signify the less stable isomer e.g., allocinnamic acid. 

We know that crotonic acid exists in cis and trans forms and to find their configurations we take the two trichlorocrotonic acids and carry out their hydrolyses. One gives fumaric acid and so crotonic (V) acid becomes the trans forms while isocrotonic acid (VI) is thus the cis form. 

Crotonic and isocrotonic acid are geometrical isomers of the structure CH3CH = CHCOOH, crotonic acid being the trans form and isocrotonic acid the cis form. Crotonic acid has the higher melting point (72°C, compared to 15.5°C) and is ordinarily a solid. 

A previous Organia Syntheses procedure for the preparation of isocrotonic acid involves the stereospecific Favorskii rearrangement of l,3-dibromo-2-butanone.6 However, the procedure is rather laborious and, in our hands, gives only a modest overall yield of acid. Isocrotonic acid has also been prepared by carbonation of cis-propenyllithium and by sodium amalgam... 

Reaction XI. Intramolecular Elimination of Water from certain Molecules. (A., 227, 242.)—When phenyl isocrotonic acid is heated, water is eliminated and a-naphthol is formed. This synthesis, which is of theoretical interest, was discovered by Fittig. It is one of the proofs of the structure of naphthalene. 

CIS-a,/ -UNSATURATED ACIDS ISOCROTONIC ACID [(-Z)-Crotonic acid]... 

B. Isocrotonic Acid. To a solution of 100 g. (1.0 mole) of potassium bicarbonate (Note 7) in 1 1. of water contained in a 2-1. three-necked round-bottomed flask equipped with a condenser, a dropping funnel, and a Teflon stirrer, 46.0 g. (0.2 mole) of l,3-dibromo-2-butanone is added over a 5-minute period... 

The yield of crude isocrotonic acid is 11.8-13.2 g. (69-77%). It is sufficiently pure for most purposes although n.m.r. analysis (Note 14) shows that the crude acid contains a small amount of the stable iraws-isomer (Note 15). The crude product cannot be stored without isomerization. 

Isocrotonic acid can be prepared by the stereospecific cis-hydrogenation of tetrolic acid3 or, mixed with the acid with sodium amalgam.4 The eis-acid can also be prepared in small amounts by isomerization of the frana-acid.6 The method herein described is much less laborious than the older procedures.2... 

Perbenzoic acid is an important reagent for the preparation of epoxides from olefinic compounds (method 126). When the epoxides are unstable in aqueous solution, glycols ate formed directly. The over-all reaction results in trans addition of hydrcscy groups to the double bond for crotonic and isocrotonic acids. ... 

CAS 3724-65-0. CH3CH CHCOOH. Exists in cis and trans isomeric forms, the latter being the stable isomer used commercially. The cis form melts at 15C and is sometimes called isocrotonic acid. 

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