Piperic acid

Piperic acid

Names
IUPAC name (2E,4E)-5-(3,4-methylenedioxyphenyl)-2,4-pentadienoic acid
Identifiers
CAS Registry Number	136-72-1 Y
ChEBI	CHEBI:37316 N
ChEMBL	ChEMBL332122 N
ChemSpider	4521337 N
EC number	226-118-4
InChI InChI=1S/C12H10O4/c13-12(14)4-2-1-3-9-5-6-10-11(7-9)16-8-15-10/h1-7H,8H2,(H,13,14)/b3-1+,4-2+ N Key: RHBGITBPARBDPH-ZPUQHVIOSA-N N InChI=1/C12H10O4/c13-12(14)4-2-1-3-9-5-6-10-11(7-9)16-8-15-10/h1-7H,8H2,(H,13,14)/b3-1+,4-2+ Key: RHBGITBPARBDPH-ZPUQHVIOBF
Jmol-3D images	Image
MeSH	C017637
PubChem	5370536
SMILES C1OC2=C(O1)C=C(C=C2)/C=C/C=C/C(=O)O
Properties
Molecular formula	C12H10O4
Molar mass	218.21 g·mol−1
Boiling point	decomposes
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
N verify (what is: Y/N?)
Infobox references

Piperic acid is a chemical often obtained by the base-hydrolysis of the alkaloid piperine^[1] from black pepper,^[2] followed by acidification of the corresponding salt.^[3] Piperic acid is an intermediate in the synthesis of other compounds such as piperonal, and as-such may be used to produce fragrances, perfumes flavorants and drugs as well as other useful compounds.

Preparation

Piperic acid can be prepared from the commercially-available alkaloid piperine, a cyclic amide containing a piperidine group, by reacting it with a hydroxide such as potassium hydroxide, then acidifying the formed piperate salt with hydrochloric acid or another acid. The toxic compound piperidine is given off during the base-hydrolysis of piperine and as-such, safety precautions should be taken.

Reactions

Reaction of piperic acid with strong oxidizers such as potassium permanganate or ozone, or a halogen such as bromine followed by sodium hydroxide causes oxidative cleavage of the double-bonds, yielding piperonal and piperonylic acid.^[4][5] Piperonal has many uses in industry and is itself a precursor to a good subsection of other chemicals. On reduction with sodium amalgam piperic acid forms α- and β-dihydropiperic acid, C₁₂H₁₂O₄, and the latter can take up two further atoms of hydrogen to produce tetrahydropiperic acid.

See also

• Piperonal
• Piperine
• Safrole
• Isosafrole
• Sesamol
• Piperonyl butoxide
• Cinnamic acid

References

1. ↑ Paul M. Dewick. (2009). Medicinal natural products : a biosynthetic approach. Chichester: A John Wiley & Sons. p. 327. ISBN 978-0-470-74167-2. 
2. ↑ http://chestofbooks.com/health/aromatherapy/The-Volatile-Oils-Vol1/Heliotropin.html
3. ↑ http://www.erowid.org/archive/rhodium/chemistry/3base/piperonal.pepper/degradation.piperine/index.html
4. ↑ http://www.freepatentsonline.com/5095128.html, Preparation process for piperonal, US Patent No. 5095128
5. ↑ http://www.erowid.org/archive/rhodium/chemistry/3base/piperonal.pepper/cleavage.piperic_acid/index.html