Another convention that you may see on the MCAT is naming carbons relative to the carbonyl group.
By this convention, the carbon adjacent to the carbonyl carbon is indicated by alpha (α). Moving
away from the carbonyl, the successive carbons are referred to as beta (β), gamma (γ), and delta (δ)
carbons. This applies on both sides of the carbonyl in the same fashion, so the carbons on both sides
of a ketone are considered alpha carbons. This will become important when we discuss α-hydrogen
acidity in Chapter 7 of MCAT Organic Chemistry Review.
MCAT Concept Check 1.3:
Before you move on, assess your understanding of the material with these questions.
What is the difference between an aldehyde and a ketone?
Aldehyde:
Ketone:
What suffixes are used for aldehydes and ketones; how are carbonyl groups named as a
substituent?
Aldehyde suffix: ; substituent prefix:
Ketone suffix: ; substituent prefix:
Fill in the common names in the following chart.
IUPAC Name Common Name
Methanal
Ethanal