Advices For Studying Organic Chemistry

H O −

An inversion of configuration

H O H O

δ−

C Cl

HH

H

δ+ δ−

C

HH

H

C Cl + Cl −

HH

H

δ−

2. Inversion of configuration can be observed when hydroxide ion reacts with
   cis-1-chloro-3-methylcyclopentane in an SN2 reaction:

OH−

An inversion of configuration

OH

+ S Cl −

N^2

+

H 3 C H

H

Cl

H

H 3 C

H

cis-1-Chloro-3-methylcyclopentane trans-3-methylcyclopentanol

1) The transition state is likely to be:

δ−

OHδ−

Leaving group departs

from the top side.

Nucleophile attacks

from the bottom side.

H

H 3 C

H

Cl

3. Inversion of configuration can be also observed when the SN2 reaction takes
   place at a stereocenter (with complete inversion of stereochemistry at the chiral
   carbon center):

H C Br

C 6 H 13

CH (^3)
Br C H
C 6 H 13
CH (^3)
(R)-(–)-2-Bromooctane (S)-(+)-2-Bromooctane

[]α^25 D = –34.25° [α]^25 D = +34.25°