23dibromobutane

2,3-Dibromobutane is a vicinal dibromide with the molecular formula C4H8Br2. Its structure can be written as CH3-CHBr-CHBr-CH3, with bromine atoms attached to the second and third carbon atoms of butane. The molecule contains two stereocenters, giving rise to two distinct stereoisomeric series: a meso form and a pair of enantiomers.

The stereoisomers consist of meso-2,3-dibromobutane (R,S) which is achiral due to an internal plane of symmetry, and the enantiomeric pair (R,R) and (S,S), which are optically active. The racemate of the enantiomers is often encountered in synthesis, while the meso form remains optically inactive.

Bromination of alkenes is a common method to prepare 2,3-dibromobutane. The reaction proceeds via anti addition of Br2 to the double bond. The stereochemical outcome depends on the geometry of the starting alkene: bromination of trans-2-butene yields the meso isomer, whereas bromination of cis-2-butene yields an enantiomeric pair (a racemate). This makes 2,3-dibromobutane a classic example in discussions of stereochemistry and diastereomerism.

Applications of 2,3-dibromobutane include its use as a synthetic intermediate in organic synthesis and as a model compound for studying vicinal dibromides and stereochemical relationships. Safety considerations are typical of halogenated hydrocarbons; bromine is corrosive and experiments should be conducted with appropriate protective equipment and in a properly equipped laboratory.