Question

1.(1 pt. each) Consider the following statements regarding Syl, SN2, E1 and E2 reactions. To which mechansims, if any, does each statement apply? If the statement can be applied to more than one mechanism, indicate each mechanism. SNI a) Involves a carbocation intermediate SNIEL b) Substitution at a stereocenter give predominantly a racemic product c) Rearrangements of the carbon skeleton are possible. EL SM d) Is greatly accelerated in protic solvents of increasing polarity SN e) Is first order in the haloalkane and first order in attacking specie EN SN7 )ED

Answer 1

a. Mainly the reaction goes carbocation intermediate is - SN1 and E1.

b. Recemic mixture of products obtain when nucleophile attack from the both side and both side attack possible only for the carbocation intermediate. So for resimic mixture product reaction goes to - SN1

C. rearrangement of carbon skeleton are possible if the reaction goes to carbocation intermediate as carbocation intermediate always favour stable carbocation formation due to stable carbocation formation there occour rearrangement. So for this rearrangement occur in SN1 and E1 as both goes to carbocation intermediate.

d. Polar protic solvent stabilise the carbocation intermediate because the large dipolemoment of the solvent . So carbocation intermediate polar protic solvent accelarate the reaction. And reaction goes through carbocation intermediate is -SN1and E1.

e. First order haloalkane undergose mainly E2 and SN2 reaction as it can not goes through carbocation intermediate because first order carbocation is very unstable.