6/11/2012 - Alkene to 1,2-Diol

Alkenes can be used in many sorts of organic reactions, and here is another use in the introduction of alcohol groups onto a molecule. A 1,2-diol is an organic molecule with two adjacent alcohol groups, as seen in the image below, and it is made through the reaction of an alkene with Osmium Tetroxide and a weak base, such as pyridine.  Then there will be a workup of water and sodium bisulfite to protinate the alcohol groups.  As seen below, highlighted in blue, the oxygen atoms come from the same osmium tetroxide molecule, resulting in the alcohol groups being syn to one another (being on the same side of the molecule).

5/19/2012 - Alkene to 1,2-dihalide

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.