The CAS register number of 7a-Methyl-2,3,5,6,7,7a-hexahydro-1H-indene-1,5-dione is 19576-08-0. It also can be called as 1H-Indene-1,5(6H)-dione,2,3,7,7a-tetrahydro-7a-methyl- and the systematic name about this chemical is 7a-methyl-2,3,7,7a-tetrahydro-1H-indene-1,5(6H)-dione. 

Physical properties about 7a-Methyl-2,3,5,6,7,7a-hexahydro-1H-indene-1,5-dione are: (1)ACD/LogP: 0.49; (2)ACD/LogD (pH 5.5): 0.49; (3)ACD/LogD (pH 7.4): 0.49; (4)ACD/BCF (pH 5.5): 1.39; (5)ACD/BCF (pH 7.4): 1.39; (6)ACD/KOC (pH 5.5): 44.09; (7)ACD/KOC (pH 7.4): 44.09; (8)#H bond acceptors: 2; (9)Polar Surface Area: 34.14Ų; (10)Index of Refraction: 1.524; (11)Molar Refractivity: 44.18 cm³; (12)Molar Volume: 144.2 cm³; (13)Polarizability: 17.51x10^-24cm³; (14)Surface Tension: 39.6 dyne/cm; (15)Enthalpy of Vaporization: 55.15 kJ/mol; (16)Boiling Point: 310.6 °C at 760 mmHg; (17)Vapour Pressure: 0.000594 mmHg at 25°C.

Preparation: this chemical can be prepared by 2-but-3-ynyl-2-methyl-[1,3]dioxolane and 1,2-bis(trimethylsilyloxy)cyclobutene. This reaction will need reagent BF₃*OEt₂ and solvent CH₂Cl₂. The yield is about 66%.

Uses of 7a-Methyl-2,3,5,6,7,7a-hexahydro-1H-indene-1,5-dione: it can be used to produce 5-hydroxy-indan-1-one at temperature of 660 ℃. This reaction time is 35 min. The yield is about 55%.

You can still convert the following datas into molecular structure:
(1)SMILES: O=C2C1(/C(=C\C(=O)CC1)CC2)C
(2)InChI: InChI=1/C10H12O2/c1-10-5-4-8(11)6-7(10)2-3-9(10)12/h6H,2-5H2,1H3
(3)InChIKey: FNYAZSZTENLTRT-UHFFFAOYAH
(4)Std. InChI: InChI=1S/C10H12O2/c1-10-5-4-8(11)6-7(10)2-3-9(10)12/h6H,2-5H2,1H3
(5)Std. InChIKey: FNYAZSZTENLTRT-UHFFFAOYSA-N