Isomerism Question Example - Organic Chemistry Advanced Level


A is a organic compound. It's molecular formula is C4H10O. This A compound does not hold optical isomerism. Also A does not react with NaOH and Na.

1. Draw all possible structures of A.

2. One of A's isomerism can be prepared by using only following reagents. Identify that isomerism and complete the block diagram of conversion.



This organic compound A contains only single oxygen atom. Therefore we can assume A can be an alcohol, an ether, an aldehyde and a ketone.

It's mentioned that, that A does not react with Na or NaOH.

Alcohols reacts with Na. Therefore A is not an alcohol.

Aldehydes and ketones reacts with NaOH( aldol condensation ).Only formaldehyde (HCHO) does not show aldol condensation. Now, we can eliminate aldehydes and ketones too.

Now we know, A is an ether

Let's draw all possible structures of A.

Isomerism structures of C4H10O


Preparing esters

Esters can be prepared by reaction between salts of alcohol ( like CH3CH2O- ) and alkyl halide ( like CH3CH2Br ) .

We have received ethanol as only organic compound. Therefore we have to start from it. We can make CH3CH2O-Na+ from reaction between C2H5OH and Na.

Add conc HBr into C2H5OH to prepare CH3CH2Br.

Lets mix both CH3CH2O-Na+ and CH3CH2Br.

Now, we can select our compound as follow.

ethoxy ethane molecule

Block Diagram

ethanol to ethoxy ethane
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