1,2-Butanediol
1,2-Butanediol is the organic compound with the formula HOCHCHCHCH. It is classified as a vic-diol. It is chiral, although typically it is encountered as the racemic mixture. It is a colorless liquid.
Preparation
This diol was first described by Charles-Adolphe Wurtz in 1859.It is produced industrially by hydration of 1,2-epoxybutane.
This process requires a ten- to twenty-fold excess of water to suppress the formation of polyethers. Depending on the amount of excess water, the selectivity varies from 70 to 92%. Sulfuric acid or strongly acidic ion exchange resins may be used as catalysts, which allows the reaction to occur under 160 °C and at slightly above atmospheric pressure.
1,2-Butanediol is a byproduct of the production of 1,4-butanediol from butadiene. It is also a byproduct of the catalytic hydrocracking of starches and sugars such as sorbitol to ethylene glycol and propylene glycol.
It can also be obtained from the dihydroxylation of but-1-ene by OsO4.