The 1,3-Isobenzofurandione, hexahydro-5-methyl- is an organic which the IUPAC name is 5-methyl-3a,4,5,6,7,7a-hexahydro-2-benzofuran-1,3-dione. With the CAS registry number 19438-60-9, it is also named as 1,2-Cyclohexanedicarboxylic anhydride, 4-methyl-; Hexahydro-4-methylphthalic anhydride.  

The 1,3-Isobenzofurandione, hexahydro-5-methyl- is clear liquid which is sensitive to moisture. It can cause serious damage to the eyes and may cause sensitization by inhalation and skin contact. So people should not breathe dust and avoid contact with skin. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. If you want to contact this product, you must wear suitable gloves and eye/face protection.

This chemical can be used in many organic synthesis. For example: It can be used in the preparation of 5-methyl-hexahydro-isoindole-1,3-dione. This reaction needs reagent 25% aq. ammonia at temperature of 240 - 245°C. The reaction time is 2 hours. The yield is 75%.
 

The other characteristics of this product can be summarized as: (1)ACD/LogP: 0.73; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 0.73; (4)ACD/LogD (pH 7.4): 0.73; (5)ACD/BCF (pH 5.5): 2.13; (6)ACD/BCF (pH 7.4): 2.13; (7)ACD/KOC (pH 5.5): 59.73; (8)ACD/KOC (pH 7.4): 59.73; (9)#H bond acceptors: 3; (10)#H bond donors: 0; (11)#Freely Rotating Bonds: 0; (12)Index of Refraction: 1.485; (13)Molar Refractivity: 41.52 cm³; (14)Molar Volume: 144.7 cm³; (15)Polarizability: 16.46×10^-24 cm³; (16)Surface Tension: 36.6 dyne/cm; (17)Enthalpy of Vaporization: 54.01 kJ/mol; (18)Vapour Pressure: 0.00115 mmHg at 25°C; (19)Tautomer Count: 4; (20)Exact Mass: 168.078644; (21)MonoIsotopic Mass: 168.078644; (22)Topological Polar Surface Area: 43.4; (23)Heavy Atom Count: 12.

People can use the following data to convert to the molecule structure. 
1.SMILES: O=C1OC(=O)C2C1CCC(C2)C; 
2.InChI: InChI=1/C9H12O3/c1-5-2-3-6-7(4-5)9(11)12-8(6)10/h5-7H,2-4H2,1H3;
3.InChIKey: FKBMTBAXDISZGN-UHFFFAOYAT