Carbonyl Compounds

Carbohydrates
 Elmhurst College
Synthesis - Aldehydes/Acids Reduction  Synthesis - Acetals  Chemistry Department
Synthesis - Ketones Synthesis - Hemiacetals  Virtual ChemBook

Introduction to Carbonyl Compounds
Aldehydes and Ketones

Introduction:

The functional group on aldehydes and ketones is a carbonyl group (double bond oxygen to a carbon). In aldehydes, the carbonyl group is on the "end" of a carbon chain, while in ketones, it is in the "middle" of a carbon chain.

The double bond in the carbonyl group is very susceptible to chemical
reactions. In this chapter, we will study oxidation and reduction reactions
and the formation of hemiacetals and acetals (new functional groups). The
primary focus of these reactions will be to eventually understand the
structures and reactions of carbohydrates.

 

Nomenclature:

The names of aldehydes and ketones are simply derived by dropping "-e" from the root and adding "-al" or "-one" respectively. A position number is needed for ketones since the carbonyl group may be on any number of several carbons in the "middle" of a chain. The carbonyl on the aldehyde is always on the number one carbon so no position number is needed.

Aldehyde

 -al

 propanal

Ketone

 -one

propanone
or
acetone
(common
name)

 

 What is the specific name or the IUPAC name of A on the left.  
 What is the specific name or the IUPAC name of A on the left.  

 

Common Aldehydes and Ketones:

Propanone (Acetone)- Chief use is a solvent since it dissolves in both water and non-polar organics. May be present in the urine of diabetics. Also used in fingernail polish remover.

Methanal (Formaldehyde) - Used to synthesize methanol and many plastics such as Bakelite and Melmac. Has antiseptic properties. Used in embalming and preservation of biological specimens.

Ethanal (Acetaldehyde) - Used to synthesize many organics. If heated with acid it polymerizes into paraldehyde which is used as an hypnotic and sedative.

Butanal - Fragrance of fresh bread.

3-phenyl-2-propenal (Cinnamaldehyde) - Causes the odor and flavor of cinnimon.

4-hydroxy-3-methoxy-benzaldehyde (Vanillin) - Flavor from vanilla beans.