IIT JEE , AIEEE Forum - Chemistry , Organic Chemistry

priyankamalviya

CH2=CHCH2Br+CuCN

------------- +NaOH

[---------------] + NaOH

------------

basically ,i'v problems with reaction of NaOH......What does it do actually?

plz explain vividly......i do not understand sch reactions..

kiran

Hi

The CN^- attacks By SN1 mecahnism. ie

1) Br^- is removed and carbo cation is formed.

2)Carbo cation rearranges to form stable 2⁰ carbocation.

3) CN^-attaches to the secondary carbon.

NaOH in aqueous state is a hydrolysing agent, ie it adds OH^- and replaces X where X can be CN^-, Cl^- etc.

4) CN is replaced from the molecule and OH is attached.

If NaOH is not aqueous it substitues H⁺ by Na ⁺ .

5) The salt CH2=C(ONa) -CH3 is formed which is in equilibrium.

Hope its clear to you.

Cheers!

neeleshv

The Br^--is lost and CN^-attacks bu SN₁mechanism and then the following compound is formed

CH₂=CHCH₂CN , Then the NaOH is a hydrolysing agent and converts CN to -COOH group. Then acid base neutralisation takes place with the next NaOH.

neeleshv

The carbocation doesn't rearrange as Allyl carbocation is more stable

rishabh29288

first Br is replaced by CN at the allylic position and then cn is oxidised to cooh