Question

a. Name each of the following alcohols.

b. Name each of the following alcohols, including the stereochemistry if cis–transisomers are possible.

Short answer

a. pentan-1-ol, 2-methylpentane-2,4-diol

b. (1S,2S)-cyclohexane-1,2-diol, 4 -methylpent-l-en-3-ol

Step-by-step solution

Rules for naming alcohols

The only difference in the naming of alcohol in relation to the naming of alkanes is in the suffix.

Alcohols have the suffix -ol.

You can look up general rules for naming alkanes in the solution.

pentan-1-ol, 2-methylpentane-2,4-diol compound

(a)

The longest continuous chain of carbon atoms should be numbered first so that the hydroxyl group gets the smallest number.

The alcohol shown in the figure below on the left is a simple alcohol that contains 5 carbon atoms and has no substituents. Therefore, the name of the alcohol shown below is pentan-l-ol.

The alcohol shown in the figure below on the right is a diol which also contains 5 carbon atoms but has a methyl group at position 2. The two hydroxyl groups are at positions 2 and 4 .

Therefore, the name of the alcohol shown below is 2-methylpentane-2,4-diol.

Hence, the above alcohols is pentan-1-ol, 2-methylpentane-2,4-diol.

(1S,2S)-cyclohexane-1,2-diol, 4 -methylpent-l-en-3-ol compound

(b)

The alcohol shown in the picture below on the left is a diol that contains 6 carbon atoms organized in a ring.

The two hydroxyl groups are located at positions 1 and 2. The relationship between the hydroxyl groups is trans as they are located on different sides.

Therefore, the name of the alcohol shown is (1S,2S)-cyclohexane-1,2-diol.

The alcohol shown in the picture below on the right is alcohol that contains 5 carbon atoms. The hydroxyl group is in position 3 and the methyl group is in position 4 . It should also be noted that there is a double bond between Cl and C2.

The name of the given compound is 4-methylpent-l-en-3-ol.

Hence, the above alcohols is (1S,2S)-cyclohexane-1,2-diol, 4 -methylpent-l-en-3-ol.