# How many chiral carbon centers does tetracycline have?

May 4, 2016

There are five chiral carbons in tetracycline.

#### Explanation:

The tetracyclines are a family of broad-spectrum antibiotics used to treat bacterial infections.

The parent member of this family is tetracycline itself:

The chiral centres are the carbon atoms with four different groups attached.

There are no internal mirror images, so every carbon atom is different.

For ease of reference, here is the numbering system for the ring carbon atoms.

The chiral centres in tetracycline and the groups attached to them are:

• $\text{C4: N, C3, C4a, H}$
• $\text{C4a: C12a, C4, C5,H}$
• $\text{C5a: C11a, C5, C6, H}$
• ${\text{C6: O, 6a, 5a, CH}}_{3}$
• $\text{C12a: O, C1, C12, C4a}$

That makes a total of five chiral centres in tetracycline.

Here's a video that might help you find the chiral centres in tetracycline.