Butanediols (also synonymous butylene glycols ) are chain-like organic compounds made up of four carbon and eight hydrogen atoms and two hydroxyl groups , i.e. diols .
Depending on the arrangement of the hydroxyl group, a distinction is made between four butanediols , neglecting the stereochemistry :
The other conceivable butanediols 1,1-butanediol and 2,2-butanediol are not stable as geminal diols according to the Erlenmeyer rule , since the hydroxyl groups are bonded to the same carbon atom.
1,2-butanediol and 1,3-butanediol are chiral and each contain a stereocenter . Therefore there are the following stereoisomers :
- ( R ) -1,2-butanediol and
- ( S ) -1,2-butanediol
- ( R ) -1,3-butanediol and
- ( S ) -1,3-butanediol.
2,3-Butanediol contains two stereocenters with the same substitution pattern, so there are three stereoisomers:
- ( R , R ) -2,3-butanediol,
- ( S , S ) -2,3-butanediol and
All butanediols are used as glycerine substitutes and solvents as well as for the synthesis of plastics and epoxy resins.