Chemistry informtion about 2,3-Dimethyl-1,3-Butadiene (CAS NO.513-81-5) is:
IUPAC Name: 2,3-Dimethylbuta-1,3-Diene
Synonyms: 2,3-Dimethyl-3-Butadiene ; 2,3-Dimethylbutadiene ; 2,3-Dimethylenebutane ; 2,3-Dimethylerythrene,Diiso-propenyl ; Biisopropenyl ; CH₂=C(CH₃)C(CH₃)=CH₂ ; Diisopropenyl ; 2,3-Dimethyl-Buta-1,3-Diene 
Product Categories: Acyclic ; Alkenes ; Organic Building Blocks ; DID - DINChemical Class ; NeatsGasoline, Diesel,&Petroleum ; Substance classes ; Alpha Sort ; D ; DAlphabetic ; Hydrocarbons ; Olefins ; Volatiles/ Semivolatiles 
MF: C₆H₁₀
MW: 82.14
EINECS: 208-172-0
Density: 0.699 g/cm3 
Melting Point: −76 °C(lit.)
Flash Point: °C
Boiling Point: 68.8 °C at 760 mmHg
Vapour Pressure: 150 mmHg at 25°C
Enthalpy of Vaporization: 29.76 kJ/mol
Refractive Index: n20/D 1.438(lit.)
Storage temp.:  2-8°C
Merck: 14,3238
BRN: 605285
Following is the molecular structure of 2,3-Dimethyl-1,3-Butadiene (CAS NO.513-81-5) is:

Raw materials are Calcium chloride-->Hydroquinone-->Pinacol .

Forms explosive polymeric peroxides on exposure to air. Explodes on contact with thiazyl fluoride. Ignites on contact with oxygen + ozone above −78°C. When heated to decomposition it emits acrid smoke and fumes. 
Hazard Codes:
F
Risk Statements:
R11:Highly flammable. 
Safety Statements:
S16:Keep away from sources of ignition. 
S23:Do not breathe vapour.
RIDADR: UN 3295 3/PG 2
WGK Germany: 3
F:
F 9 Keep under nitrogen. 
HazardClass: 3
PackingGroup: II

 2,3-Dimethyl-1,3-Butadiene (CAS NO.513-81-5) is a clear colorless liquid. To protect yourself, you can put on eyeshields, faceshields, full-face respirator (US), gloves, multi-purpose combination respirator cartridge (US), type ABEK (EN14387) respirator filter.