If we start with a single enantiomer of an alcohol, we would obtain a mixture of both enantiomers...help!?

Question

of the alkly halide product with little to not optical activity. Explain.

Sn1 reaction.

Answer 1

Once the hydroxyl group leaves the alcohol, the structure would lose its pyramidal shape and flatten into a two-dimensional shape. The halide ion would add from either side, having a 50% chance of attaching from either side. Once halogenated, the new molecule would again be optically active but you would have an equal abundance of both R and L enantiomers. This follows one of the rules of stereochemistry in that optically inactive reactants (in this case HX) always yield optically inactive products.