Question

pentanol has four structural isomers that are primary alcohols.how many of these primary alcohols have a chiral carbon atom?

Answer 1

Have you drawn them yet?
You need to identify the asymmetrical carbon atoms.

Answer 2

Faris it cant be Chiral when its a primary Alcohol
1) CH3CH2CH2CH2CH2OH
2)CH3CH2CH(CH3)CH2OH
3)CH3CH(CH3)CH(OH)CH3
4)CH3CH2CH2CH(OH)CH3
5)CH3CH(CH3)CH2CH2OH
6)CH3C(CH3)2CH2OH
7)CH3CH2CH(OH)CH2CH3
8)CH3CH2C(OH)CH3CH3
9)CH3CH2C(CH3)2OH

Answer 3

The chiral carbon atom is not necessarily the one holding the alcohol group.

Answer 4

but faris asked a primary alcohol being chiral

Answer 5

@Abmon98 The question doesn't say that the carbon with the alcohol on it is chiral. You are quite right, having a primary alcohol implies that the carbon attached to the alcohol is attached to two hydrogen, which will automatically make it not chiral.

Primary alcohol simply is a name for a hydrocarbon with a primary alcohol group attached.

Answer 6

i misunderstood the question, iam sorry everyone :/

Answer 7

Well lets see.

CH3-CH2-CH2-CH2-CH2-OH is 1-pentanol(or pentan-1-ol) and it is achiral.

There is another primary alcohol with 5 carbons and it is 2-methylbutan-1-ol and looks like this:

This is chiral because it has a carbon attached to an ethyl group, the carbon attached to the OH, a methyl group, and a hydrogen.

3-methylbutan-1-ol looks similar except the methyl group is attached to the 3rd carbon.
Since this has a carbon attached to 2 methyl groups it is achiral.

2,2-dimethylpropanol is also achiral because it has a carbon attached to 3 methyl groups

Out of the primary alcohols only 1 with 5 carbons is chiral.