The 2H-Pyran-2-one,6-ethyltetrahydro-, with the CAS registry number 3301-90-4, is also known as 5-Hydroxyheptanoic acid lactone. Its EINECS number is 221-972-4. This chemical's molecular formula is C₇H₁₂O₂ and molecular weight is 128.17. What's more, its systematic name is 6-ethyltetrahydro-2H-pyran-2-one. 

Physical properties of 2H-Pyran-2-one,6-ethyltetrahydro- are: (1)ACD/LogP: 0.82; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 0.82; (4)ACD/BCF (pH 5.5): 2.49; (5)ACD/KOC (pH 5.5): 66.83; (6)#H bond acceptors: 2; (7)#H bond donors: 0; (8)#Freely Rotating Bonds: 1; (9)Polar Surface Area: 26.3 Å²; (10)Index of Refraction: 1.431; (11)Molar Refractivity: 34.12 cm³; (12)Molar Volume: 131.5 cm³; (13)Polarizability: 13.52×10^-24cm³; (14)Surface Tension: 28.5 dyne/cm; (15)Density: 0.974 g/cm³; (16)Flash Point: 85.6 °C; (17)nthalpy of Vaporization: 46.35 kJ/mol; (18)Boiling Point: 227 °C at 760 mmHg; (19)Vapour Pressure: 0.0795 mmHg at 25°C.

Preparation: this chemical can be prepared by 5-oxo-heptanal at the temperature of 25 °C. This reaction will need reagents i-PrSH, SmI₂ and solvent tetrahydrofuran with the reaction time of 1 hour. The yield is about 91%.

You can still convert the following datas into molecular structure:
(1)SMILES: O=C1OC(CC)CCC1
(2)InChI: InChI=1S/C7H12O2/c1-2-6-4-3-5-7(8)9-6/h6H,2-5H2,1H3
(3)InChIKey: JFVQYQDTHWLYHG-UHFFFAOYSA-N