Preparations of Aldehydes and Ketones

Question 1

What can we prepare from primary alcohols?

Answer 1

Aldehydes (oxidation)

Question 2

What can we prepare from secondary alcohols?

Answer 2

Ketones(oxidation)

Question 3

Method of preparation from volatile alcohols

Answer 3

Dehydrogenation (alcohol vapors are passed over metal catalysts like Ag or Cu)

Question 4

Another method from alkenes

Answer 4

Ozonolysis of alkenes and reaction with zinc and h20.

Question 5

Hydration of which alkyne forms an aldehyde

Answer 5

Ethyne in the presence of h2so4 and hgso4 gives acetaldehyde.

Question 6

Rosenmund Reaction

Answer 6

Acyl Chloride + H2/Pd-BaSO4 gives an aldehyde

Question 7

Stephen Reaction

Answer 7

Nitriles(RCN) + SnCl2 +HCl gives imine (RCH=NH) on hydrolysis gives aldehydes

Question 8

From Esters

Answer 8

Esters + DIBAL-H/H2O gives aldehydes

Question 9

Etard Reaction

Answer 9

CrO2Cl2 + toluene on hydrolysis gives aldehydes

Question 10

What other reagent can react with toluene to produce aldehydes

Answer 10

Chromic oxide CrO3 (Benzylidene diacetate on hydrolysis with acid)

Question 11

Which halogen can react with toluene to produce an aldehyde

Answer 11

Chloride

Question 12

Commercial method of manufacture of benzaldehyde

Answer 12

Side chain chlorination of toluene

Question 13

Gatterman - Koch Reaction

Answer 13

Benzene + CO/HCL/ Anhydrous AlCl3/CuCl give benzaldehyde

Question 14

How is dialkylcadmium prepared?

Answer 14

Grignard reagent + Cadmium Chloride(2R-Mg-X + CdCl2 —-> R2Cd + 2Mg(x)Cl)

Question 15

How are ketones formed from acyl chloride

Answer 15

Dialkylcadmium + acyl chloride gives ketones.

Question 16

How are ketones prepared from Nitrile

Answer 16

Nitriles + Grignard Reagent followed by hydrolysis gives ketones

Question 17

Friedel Crafts acylation

Answer 17

Benzene or substituted Benzene + Acid chloride in the presence of Anhydrous AlCl3 produces a ketone.