stereocenters

Problem # 525

On the molecule below, mark each stereocenter with an asterisk. (Note: in some textbooks, stereocenters are referred to as stereogenic centers, chirality centers, or asymmetric centers).

Solution

To be a stereocenter you need to:

be a carbon
be sp³ hybridized (all single bonds)
have four different substituents

Are there other types of stereocenters? Of course! ( sp³ sulfur atoms, for example). But in undergraduate organic chemistry, 99% of all sterocenters you come across will be sp³ hybridized carbon atoms.

So in the molecule below, there are four stereocenters.

Note that the sp²(alkene) carbons can't be sterocenters.