7467. Piperic Acid

Nomenclature

CAS number: 5285-18-7
5-(1,3-Benzodioxol-5-yl)-2,4-pentadienoic acid; 5-(3,4-methylenedioxyphenyl)-2,4-pentadienoic acid.
C12H10O4; mol wt 218.21.
C 66.05%, H 4.62%, O 29.33%.

Description and references

Early literature treats the title compound without specifying stereochemistry; however, four isomers exist: piperinic acid (E,E); isochavicinic acid (E,Z); isopiperinic acid (Z,E); chavicinic acid (Z,Z). Physical constants given in early references for piperic acid agree with those of piperinic acid. See Beilstein 19, 281; suppl. II, 300. Synthesis of (E,E)-form: L. von Babo, E. Keller, J. Prakt. Chem. 72, 53 (1857); A. Ladenburg, M. Sholtz, Ber. 27, 2958 (1894); of (E,Z)-form: H. Lohaus, H. Gall, Ann. 517, 278 (1935); of (Z,E)-form: E. Ott, F. Eichler, Ber. 55, 2653 (1922); of (Z,Z)-form: idem, loc. cit.; H. Lohaus, H. Gall, loc. cit.; of all isomers: R. Grewe et al., Ber. 103, 3752 (1970); R. De Cleyn, A. Verzele, Bull. Soc. Chim. Belg. 81, 529 (1972).

Chemical structure

Derivative

(E,E)-Form.

Nomenclature

CAS number: 136-72-1
Piperinic acid; piperins"aure (German).

Properties

Needles from alc. Colorless when freshly prepd, rapidly turns yellow on exposure to light. mp 216-217°. Sublimes as yellow needles with partial decompn. uv max (methanol): 340 nm (ε 28800). Sol in 50 parts boiling alcohol, 275 parts abs alcohol at 25°. Practically insol in water, ether, benzene, carbon disulfide.

Derivative

(E,Z)-Form.

Nomenclature

CAS number: 495-87-4
Isochavicinic acid.

Properties

Yellow crystals from methanol/water, sublimes as needles. mp 134-136° (Lohaus, Gall); 143° (Grewe). uv max (methanol): 335 nm (ε 14500). Sol in methanol, benzene.

Derivative

(Z,E)-Form.

Nomenclature

CAS number: 495-88-5
Isopiperinic acid.

Properties

Needles from benzene. mp 145° (Ott, Eichler); 153° (Grewe); 138° (DeCleyn, Verzele). uv max (methanol): 328 nm (ε 22000). Sol in benzene.

Derivative

(Z,Z)-Form.

Nomenclature

CAS number: 495-89-6
Chavicinic acid.

Properties

Amorphous yellow granules from benzene. Wide disparities in mp have been reported: 200-202° (Ott, Eichler); 130° (Grewe); 120° (De Cleyn, Verzele). uv max (methanol): 335 nm (ε 17500). 0.55 g sol in 16 g boiling 95% alcohol, and in 65 g boiling benzene.