# How many chiral centers are there in cholesterol?

Aug 11, 2015

There are eight chiral centres in cholesterol.

#### Explanation:

The structure of cholesterol with its numbering is shown below.

Remember that bond-line structures don't show the hydrogen atoms that are attached to carbon.

There is no internal plane of symmetry, so every carbon atom is different.

Each chiral carbon must have four different groups.

I have circled the chiral centres in the molecule

The eight chiral centres (with the attached groups) are:

1. $\text{C3 (OH, C4, C2, H)}$
2. $\text{C8 (C9, C14, C7, H)}$
3. $\text{C9 (C10, C8, C11, H)}$
4. $\text{C10 (C5, C9, C1, C19)}$
5. $\text{C13 (C14, C17, C12, C18)}$
6. $\text{C14 (C13, C8, C15, H)}$
7. $\text{C17 (C13, C20, C16, H)}$
8. $\text{C20 (C17, C22, C21, H)}$