Question

What happens to a ketone in the base?

Answer 1

Ketone:

1. The carbonyl group is attached to the two carbon atoms.
2. The common name of a ketone is derived from the naming of the alkyl group (R) and aryl group (${\mathrm{R}}^{\text{'}}$) which are bonded to a carbonyl group.
3. The IUPAC name of the ketone is derived from the name of alkane by replacing the ending -e with -one respectively.
4. For example, ${\mathrm{CH}}_3{\mathrm{COCH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3$ is a ketone compound so the common IUPAC name is Methyl n-propyl ketone and Pentan-2-one.

Ketone-base reaction mechanism:

1. The reaction between the ketone and base is called the aldol condensation reaction.
2. There is at least one $\mathrm{\alpha }-\mathrm{hydrogen}$ that reacts in the presence of alkali as a catalyst to produce $\mathrm{\beta }-\mathrm{hydroxy}$ ketone which is also known as ketol.
3. The removal of the water molecule during the heating of ketol and the form of carbonyl compounds is called the aldol condensation product.
4. The reaction mechanism between ketone and base is shown below:

STEP 1:Barium hydroxide as a base reacts with ketone compound (Propanone).

STEP 2: 4-Hydroxy-4-methyl pentane-2-one as a Ketol formation.

STEP 3: 4-Methylpent-3-en-2-one as an aldol condensation product with the removal of water.