Topic 17 Organic 2 Notes

All 4 substituents on the central carbon must be different.

Enantiomers.

Non-superimposable mirror images of each other.

The carbon with 4 different groups attached. Often labelled with *. A molecule can have more than one chiral centre.

It can rotate the plane of polarised light.

Term given to chiral compounds because they rotate the plane of polarised light.

Optically inactive.

For every molecule in the mixture that rotates the plane of polarisation in one direction, there is an enantiomer that rotates the plane in the opposite direction.

There is an equal concentration of both enantiomers, so the rotations cancel out.

The wedge comes towards you, out of the plane. The dashed line goes away from you, into the plane. The two straight lines are next to each other.

It has only one species in the rate equation.

It has 2 species in the rate equation.

Cl - can approach the cation from either side as the molecule is planar. Thus, both enantiomers form; the race mate is not optically active.

Rear-side attack, the chloride attacks the partially positive chiral carbon. Inversion occurs, and the Cl switches with the OH group. Only one enantiomer is formed, so the product is optically active.

Aldehydes & ketones.

Almost always 3 or 4 oxygens.

Just the element.

Reduced form of phosphorous.

Oxidised form of phosphorous.

Use oxidation states, and work backwards from the acid.

It forms a more stable carbocation by the positive inductive effect.

R-CHO

R-COR’

Aldehydes.