Question

write the mechanism of the following reaction:CH3-CO-CH2-CH3->(i)NH2-NH2/(ii)NaOC2H5->C4H10​

Answer 1

Answer:

The –OH group in the alcohol donates two electrons to H

+

from the acid reagent, forming an alkyloxonium ion. This ion acts as a very good leaving group which leaves to form a carbocation. The deprotonated acid (the nucleophile) then attacks the hydrogen adjacent to the carbocation and form a double bond.Primary alcohols undergo bimolecular elimination (E

2

mechanism) while secondary and tertiary alcohols undergo unimolecular elimination (E

1

mechanism). Oxygen donates two electrons to a proton from sulfuric acid H

2

SO

4

, forming an alkyloxonium ion. Then the nucleophile HSO

4

–

back-side attacks one adjacent hydrogen and the alkyloxonium ion leaves in a concerted process, making a double bond.