2 3
Preparation
of Ketones
Rationalised 2023-24
234
Chemistry
2 From nitriles
Treating a nitrile with Grignard reagent followed by hydrolysis yields
a ketone Give names of the reagents to bring about the following
transformations:
(i) Hexan-1-ol to hexanal
(ii)
Cyclohexanol to cyclohexanone
(iii) p-Fluorotoluene to
(iv)
Ethanenitrile to ethanal
p-fluorobenzaldehyde
(v) Allyl alcohol to propenal
(vi)
But-2-ene to ethanal
(i) C5H5NH+CrO3Cl-(PCC)
(ii)
Anhydrous CrO3
(iii) CrO3 in the presence
(iv)
(Diisobutyl)aluminium
of acetic anhydride/
hydride (DIBAL-H)
1