The 4H-Pyran-2-carboxylicacid, 5-hydroxy-4-oxo-, with the CAS registry number 499-78-5 and EINECS registry number 207-891-7, has the systematic name of 5-hydroxy-4-oxo-4H-pyran-2-carboxylic acid. It belongs to the product category of API intermediates. And the molecular formula of the chemical is C₆H₄O₅. What's more, it is harmful if swallowed.

The characteristics of 4H-Pyran-2-carboxylicacid, 5-hydroxy-4-oxo- are as followings: (1)ACD/LogP: -0.79; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -4.31; (4)ACD/LogD (pH 7.4): -4.66; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 5; (10)#H bond donors: 2; (11)#Freely Rotating Bonds: 2; (12)Polar Surface Area: 61.83 Å²; (13)Index of Refraction: 1.66; (14)Molar Refractivity: 31.69 cm³; (15)Molar Volume: 85.8 cm³; (16)Polarizability: 12.5×10^-24cm³; (17)Surface Tension: 102.6 dyne/cm; (18)Density: 1.819 g/cm³; (19)Flash Point: 187.7 °C; (20)Enthalpy of Vaporization: 77.92 kJ/mol; (21)Boiling Point: 420.7 °C at 760 mmHg; (22)Vapour Pressure: 7.71E-09 mmHg at 25°C.
 
Addtionally, the following datas could be converted into the molecular structure:
(1)SMILES: O=C1\C=C(/O/C=C1/O)C(=O)O
(2)InChI: InChI=1/C6H4O5/c7-3-1-5(6(9)10)11-2-4(3)8/h1-2,8H,(H,9,10)
(3)InChIKey: UUUICOMMFFTCHS-UHFFFAOYAV