Guest

explain in detail about SN1 and SN2 reactions

explain in detail about SN1 and SN2 reactions

Grade:12

1 Answers

vikas askiitian expert
509 Points
11 years ago

SN1 ) this reaction proceeds  according to these steps

1) hetrolatically cleavage of carbon halogen bond

2)formation of carbocation(rearrangment)

3)formation of new bond

eg) CH3CH2CH2Cl + KOH (aq) = CH3CH(OH)CH3

mechanism

   CH3CH2CH2Cl  =  CH3CH2CH2+       ( 1O CARBOCATION)

 1o carbocation rearranges to 2o by hydride shift , to gain stablity ...

    CH3CH+CH3 + OH- (neucleophile) = CH3CH(OH)CH3

order of reactivity  = benzyl>allyle>3o >2o>1o                  (on the basis of carbocation stablity))

 

SN2)

in this reaction breaking of bonds & formation of new bonds take place samultaneously during a transition state...

in this state neuclephile(OH-) attacks from back side and at the same time carbon halogen bond breaks and product is formed...

this transition state is pentavalent & attaking neuclophile ,halogen are  along axial bond ......no rearrangment occures...

eg)

     CH3CH2CH2Cl + OH- => CH3CH2CH2OH

this reaction favoures  aprotic solvents & strong base ......

order of reactivity = 10>2o>30              (less staric hindered alkyle halide will react fast )

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free