By Dehydrogenation of Alcohol: On passing the vapor of primary alcohol on copper heated at 300°C, aldehyde and secondary alcohol vapor is formed to form ketone. And H2 gas is liberated.
RCH2OH → RCHO + H2
CH3OH → HCHO + H2
Reduction of Chlorides Acid: Reduction of chloride acids by Rozenmund reaction in the presence of a paledium catalyst containing barium sulfate to form aldehyde. Ketones cannot be obtained by this method.
By calcium salts of fatty acids: On heating calcium formate alone (dry distillation) formaldehyde and on heating with calcium salt of any other fatty acid, aceteldyhide is formed.
By Alkynes: Acetaldehyde is formed when acetylene is passed through 20% H2SO4 in the presence of 1% HgSO4 at 60°C. The ketone is formed when the higher member of the acetylene series is taken.
CH≡CH (acetylene) + H2O → CH3CHO
CH3 – C ≡ CH (Propene) + H2O → CH3COCH3
By Grignard reagent:- On hydrolysis of Grignard reagent with ethyl formate, aldehyde is formed.
Grignard reagent reacts with chloride acids to form ketone.
example
By ozonisation of alkynes:
RCH = Ozonisation of CHR type alkynes gives aldehydes.