Etard Reaction

Assertion : Etard reaction helps to stop the oxidation of toluene at the aldehyde stage. Reason : Chromyl chloride oxidises methyl group to a chromium complex, which on hydrolysis gives corresponding benzaldehyde.

(a) Write the reactions involved in the following: (i) Etard reaction (ii) Stephen reduction (b) How will you convert the following in not more than two steps: (i) Benzoic acid to Benzaldehyde (ii) Acetophenone to Benzoic acid (iii) Ethanoic acid to 2-Hydroxyethanoic acid.

(a) Write the reactions involved in the following: (i) Etard reaction (ii) Stephen reduction (b) How will you convert the following in not more than two steps: (i) Benzoic acid to Benzaldehyde (ii) Acetophenone to Benzoic acid (iii) Ethanoic acid to 2-Hydroxyethanoic acid.

The oxidation of aryl methyl or cyclo alkyl methyl by the treatment with chromyl chloride to an aldehyde via the formation of esters is known as Etard reaction. The oxidation stops at aldehyde stage because the product of the reaction is acylal, R - CH(OCOCH_3)_2 which is resistance to oxidation with this reagent. The acylal on hydrolysis gives aldehyde. Which of the other reactions will produce benzaldehyde ?

(a) Phthalaldehyde overset(Conc.NaOH)(to) Product (to) Cannizzaro reaction (b) alpha - Methylacylohexanone underset(Delta)overset(NaOH)(to) Product (to) Aldol condensation ( c) Toluene underset(H_(3)O^(+))overset(CrO_(2)Cl_(2)//CS_(2))(to) Product (to) Etard reaction (d) Benzene +CO+HCloverset(AlCl_(3))(to) Product (to) Gattermann's Koch reaction (e) Benezene +HCN+HCloverset(AlCl_(3))(to) Product (to) Gattermann's aldehyde synthesis Which of the following is correct set :

The oxidation of aryl methyl or cyclo alkyl methyl by the treatment with chromyl chloride to an aldehyde via the formation of esters is known as Etard reaction. The oxidation stops at aldehyde stage because the product of the reaction is acylal, R - CH(OCOCH_3)_2 which is resistance to oxidation with this reagent. The acylal on hydrolysis gives aldehyde. Which of the following compounds give benzo-phenone upon treating with Cr O_2 Cl_2 ?