Question

Give name of the reagent to bring about the following transformation:

$A$: Hexan-1-ol to hexanal

$B$: Cyclohexanol to cyclohexanone

$C$: p-fluorotoluene to p-fluorobenzaldehyde

$D$: Ethanenitrile to ethanal

$E$: Allyl alcohol to propenal

$F$: But-2-ene to ethanal

Answer 1

$A$:

Suitable reagent for the conversion of hexan-1-ol to hexanal:

$\text{PCC}$ (Pyridinium chlorochromate) is an oxidizing reagent which is used to convert primary alcohols to aldehydes and secondary alcohol to ketones.

The structure of $\text{PCC}$ is given below:


Hexan-1-ol reacts with $\text{PCC}$ and gives hexanal as a product.

This reaction can be given as:

$B$:

Suitable reagent for the conversion of cyclohexanol to cyclohexanone:
Anhydrous $Cr{O}_3$ converts primary alcohols and aldehydes to carboxylic acids and secondary alcohols to ketones. Here, anhydrous $Cr{O}_3$ is an oxidizing agent.


Cyclohexanol reacts with anhydrous $Cr{O}_3$ and gives cyclohexanone as a product.

$C$:

Suitable reagent for the conversion of p-fluorotoluene to p-fluorobenzaldehyde:

Here, $Cr{O}_3$ in the presence of acetic anhydride and $Cr{O}_{2}C{l}_2/C{S}_2$ are strong oxidizing agents which can convert p-fluorotoluene to p-fluorobenzaldehyde
Both reactions can be represented as:



$D$:

Suitable reagent for the conversion of ethanenitrile to ethanal :

DIBAL-H (Di-isobutyl aluminium hydride) is a selective reducing agent which can reduce nitriles to the corresponding aldehydes.
The reaction is done in inert and moisture free atmosphere.


When ethanenitrile is reduced by DIBAL-H, ethanal is produced.
This reaction can be given as:

$E$:

Suitable reagent for the conversion of allyl alcohol to propenal:

$\text{PCC}$ (Pyridinium chlorochromate) is an oxidizing reagent which is used to convert primary alcohols to aldehydes and secondary alcohol to ketones and PCC don’t oxidize double bonds.

The structure of $\text{PCC}$ is given below:



When allyl alcohol oxidized by $\text{PCC}$, it gives propenal. $\text{PCC}$ being a mild oxidizing agent, it does not oxidize double bond.

This reaction can be given as:



$F$:

Suitable reagent for the conversion of but-2-ene to ethanal:
Ozone is a very reactive allotrope of oxygen. The reaction of ozone with alkenes causes the oxidative cleavage of the alkenes.
The ozonolysis of but-2-ene gives 2-moles of ethanal.

This reaction can be given as: