Molecule structure of 1-Propen-1-one, 2-methyl- (CAS NO.598-26-5):

IUPAC Name: 2-Methylprop-1-en-1-one 
Molecular Weight: 70.08984 g/mol
Molecular Formula: C₄H₆O 
Density: 0.775 g/cm³ 
Boiling Point: 34 °C at 760 mmHg 
Index of Refraction: 1.373
Molar Refractivity: 20.59 cm³
Molar Volume: 90.3 cm³
Polarizability: 8.16×10^-24 cm³
Surface Tension: 8.6 dyne/cm 
Enthalpy of Vaporization: 27.92 kJ/mol
Vapour Pressure: 541 mmHg at 25 °C
XLogP3-AA: 1.7
H-Bond Acceptor: 1
Exact Mass: 70.041865
MonoIsotopic Mass: 70.041865
Topological Polar Surface Area: 17.1
Heavy Atom Count: 5
Complexity: 63.7
Canonical SMILES: CC(=C=O)C
InChI: InChI=1S/C4H6O/c1-4(2)3-5/h1-2H3
InChIKey: VDOKWPVSGXHSNP-UHFFFAOYSA-N

 1-Propen-1-one, 2-methyl- (CAS NO.598-26-5) is used in organic synthesis.

 2-Methyl malonic acid and acetic anhydride in the presence of a small amount of concentrated sulfuric acid at room temperature for 2d, generating 2-methyl malonic anhydride. Add a small amount of powdered barium carbonate, in the 133Pa pressure below the first micro-heat, heated to 60 °C, steamed out of acetic anhydride and acetic acid. Then the residual heat decomposition of 2-methyl malonic anhydride, about 100 °C, escape of carbon dioxide and 2-methyl vinyl ketone.

Upon exposure to air it forms the very unstable explosive peroxide poly(peroxyisobutyrolactone). The peroxide is heat- and friction-sensitive and will also explode upon evaporation. When heated to decomposition it emits acrid smoke and fumes. See also PEROXIDES, INORGANIC; PEROXIDES, ORGANIC.

 1-Propen-1-one, 2-methyl- (CAS NO.598-26-5) is yellow liquid.