Question

How can ethanol be converted to propanone?

Answer 1

Hint: Ethanol is a two-carbon aldehyde, and propanone is a three carbon ketone. The first step is to make a Carbon- Carbon bond, and the Grignard reagent would be the best choice.

Complete step by step answer:

Reaction of Ethanol with $Zn-Hg-HCl+$$\mathrm{\Delta }$ to give out Ethane $\left(CH3-CH3\right)$[ Clemmensen Reduction]
Reaction of Ethane with $CI2$ in presence of sunlight to give $CH3-CH2-CI$[ Clemmensen Reduction]
Reaction of $CH3-CH2+CI$ with $CH3-CI$ in presence of dry ether and $Na$ to give Propane $\left(CH3+CH2-CH3\right)$[Wurtz Reaction]
Reaction of Propane with $CI2$ in presence of sunlight to give $CH3-CH2-CH2-CI$
Reaction of $CH3-CH2-CH2-CI$ with $alcKOH$ to give $CH3-CH=CH2$
Reaction of $H2O$ with $H^{+}$to give $CH3-CH\left(OH\right)-CH3$
Oxidizing $CH3-CH\left(OH\right)-CH3$ with $K2Cr2O7$ to give Ketone as the only product and we have $CH3-CO-CH3$(propanone) .

Note: Aldehydes and ketones can be prepared by oxidation of primary and secondary alcohols. Oxidation of alcohols involves the formation of a Carbon – Oxygen double bond with cleavage of an O-H and C-H bonds.