Yet again another simple reaction takes us to working with alkenes, a major tool in an organic chemists' arsenal of reactions. This reaction here is a reaction of an alkene to a 1,2-dihalide where an alkene is reacted with a molecular halide X2 (F2, Cl2, Br2, I2) and dichloromethane as a solvent. What happens is that the two halides go anti to one another so that they are opposite sides of the molecule.
