Molecule structure of 2-Cyclopenten-1-one, 3-ethyl-2-hydroxy- (CAS NO.21835-01-8):

IUPAC Name: 3-Ethyl-2-hydroxycyclopent-2-en-1-one 
Molecular Weight: 126.1531 g/mol
Molecular Formula: C₇H₁₀O₂ 
Density: 1.156 g/cm³ 
Boiling Point: 258.3 °C at 760 mmHg 
Flash Point: 107.2 °C
Index of Refraction: 1.53
Molar Refractivity: 33.7 cm³
Molar Volume: 109 cm³
Polarizability: 13.36×10^-24 cm³
Surface Tension: 45.4 dyne/cm 
Enthalpy of Vaporization: 57.6 kJ/mol
Vapour Pressure: 0.00204 mmHg at 25 °C
XLogP3-AA: 0.7
H-Bond Donor: 1
H-Bond Acceptor: 2
Rotatable Bond Count: 1
Tautomer Count: 21
Exact Mass: 126.06808
MonoIsotopic Mass: 126.06808
Topological Polar Surface Area: 37.3
Heavy Atom Count: 9
Complexity: 168
Canonical SMILES: CCC1=C(C(=O)CC1)O
InChI: InChI=1S/C7H10O2/c1-2-5-3-4-6(8)7(5)9/h9H,2-4H2,1H3
InChIKey: JHWFWLUAUPZUCP-UHFFFAOYSA-N
Product Categories: pharmacetical; C7 to C8; Carbonyl Compounds; Ketones; Alphabetical Listings; E-F; Flavors and Fragrances

 2-Cyclopenten-1-one, 3-ethyl-2-hydroxy- (CAS NO.21835-01-8) is used as food flavors which is allowed to use by GB 2760--1996.

 2-Cyclopenten-1-one, 3-ethyl-2-hydroxy- is made from 5-yl 3,5-2-ethoxy-formyl-2-cyclopentene-2-ol-1-ones and phosphate compounds.

Hazard Codes: Xn
Risk Statements: 20/22 
R20/22:Harmful by inhalation and if swallowed.
Safety Statements: 26-36 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36:Wear suitable protective clothing.
WGK Germany: 3

 2-Cyclopenten-1-one, 3-ethyl-2-hydroxy- (CAS NO.21835-01-8) is also named as 2-Hydroxy-3-ethyl-2-cyclopenten-1-one ; 2-Hydroxy-3-ethyl-2-cyclopentene-1-one ; 3-Ethyl-2-cyclopenten-2-ol-1-one ; 3-Ethyl-2-hydroxy-2-cyclopenten-1-one ; EINECS 244-606-5 ; FEMA No. 3152 .