Haloalkanes And Haloarenes Ques 23

23. In an $S_N 1$ reaction on chiral centres there is :

[2015 RS]

(a) $100 \%$ racemization

(b) inversion more than retention leading to partial racemization

(c) $100 \%$ retention

(d) $100 \%$ inversion

Show Answer

Solution:

  1. (b) In $S_N 1$ reaction, carbocation a planar species as intermediate is formed.

So attack from below or above the plane can take place. If $50 \%$ attack below and above the plane of carbocation take place than $100 \%$ racemization occurs but it may not be highly probable.

i.e. if inversion occurs more than retention leading to partial racemization.