Asparagusic acid

Asparagusic acid

Names
IUPAC name 1,2-Dithiolane-4-carboxylic acid
Other names 1,2-Dithiacyclopentane-4-carboxylic acid
Identifiers
CAS Number	2224-02-4 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:18091 Y
ChemSpider	15819 Y
KEGG	C01892 Y
PubChem	16682
UNII	VAD3XV509R N
InChI InChI=1S/C4H6O2S2/c5-4(6)3-1-7-8-2-3/h3H,1-2H2,(H,5,6) Y Key: AYGMEFRECNWRJC-UHFFFAOYSA-N Y InChI=1/C4H6O2S2/c5-4(6)3-1-7-8-2-3/h3H,1-2H2,(H,5,6) Key: AYGMEFRECNWRJC-UHFFFAOYAA
SMILES O=C(O)C1CSSC1
Properties
Chemical formula	C4H6O2S2
Molar mass	150.21 g·mol−1
Appearance	Colorless solid
Density	1.50 g cm−3
Melting point	75.7 to 76.5 °C (168.3 to 169.7 °F; 348.8 to 349.6 K)
Boiling point	323.9 °C (615.0 °F; 597.0 K) at 760mmHg
Hazards
Flash point	149.7 °C (301.5 °F; 422.8 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Asparagusic acid is an organosulfur compound with the molecular formula C₄H₆O₂S₂ and is systematically named 1,2-dithiolane-4-carboxylic acid. The molecule consists of a cyclic disulfide functional group (a 1,2-dithiolane) with a carboxylic acid side chain. It is found in asparagus and is believed to be the metabolic precursor to odorous sulfur compounds responsible for the distinctive smell of urine which has long been associated with eating asparagus.

The material was originally isolated from an aqueous extract of Asparagus officinalis, a spring vegetable. It is a derivative of the cyclic disulfide organic compound 1,2-dithiolane with a carboxylic acid functional group bound to carbon-4 of the heterocycle. Biosynthetic studies revealed that asparagusic acid is derived from isobutyric acid. Asparagusic acid is a colorless solid with a melting point of 75.7–76.5 °C, higher than that of the corresponding dithiol, dihydroasparagusic acid (or γ,γ-dimercaptoisobutyric acid), at 59.5–60.5 °C.

A convenient synthesis of asparagusic acid has been developed from a commercially-available diethyl malonate derivative starting material, improving on the prior method of Jansen. Diethyl bis(hydroxymethyl)malonate is treated with hydroiodic acid to yield β,β'-diiodoisobutyric acid after decarboxylation and ester hydrolysis (with removal of volatile ethanol and carbon dioxide). Dihydroasparagusic acid, the reduced (dithiol) form of asparagusic acid, is produced by sequential reaction with sodium trithiocarbonate (Na₂CS₃) and sulfuric acid; subsequent oxidation with hot dimethyl sulfoxide yields asparagusic acid.