Practice Problem 10

Which of the following compounds would form enantiomers because the molecule is chiral?

Solution

The second carbon atom in 2-bromo-2-methylbutane contains two identical CH₃ substituents. As a result, this compound is achiral and does not form enantiomers.

The second carbon atom in 1-bromo-2-methylbutane carries four different substituents: H, Br, CH₃, and CH₂CH₃. As a result, this molecule is chiral and it forms enantiomers.

Note: Every object with the possible exception of the vampires found on late-night TV has a mirror image. The relevant question is whether the mirror image can be superimposed on the source of the image. If it can, the object is not chiral (achiral). If it cannot, the object is chiral and it can exist as a pair of stereoisomers.