The document discusses chiral molecules and their reactions. Chiral molecules have non-superimposable mirror images due to having four different groups attached to a carbon atom without symmetry. There are three major reactions for chiral molecules: retention, where the configuration of substrate and product remain the same; inversion, where the isomer converts to the other form through an SN2 mechanism; and racemization, where a second chiral center forms diastereomers.

1. Lecture by
S.Mathivanan., M.Pharm
Asst professor
Pharmacy.
Reactions of chiral molecules

2. Chiral molecules
 Chiral molecule has non super imposable
mirror image
 Example : Enantiomers
 It generally has chiral carbon (4 diff groups
attached to a carbon atom)
 It do not have elements of symmetry
 If n = no. Of chiral atom, then number of isomers
= 2n

3. Achiral molecules
 It has superimposable mirror images.
 Example : Meso compounds
 It has one or more elements of symmetry such as
plane of symmetry.

4. Reactions of chiral molecules
 Chiral molecules undergoes Three major
reactions :
1) Retention
2) Inversion
3) Racemisation

5. 1. Retention : Bond at chiral carbon do not break :
Configuration of substrate and product remains same
R isomer  R isomer
S isomer S isomer

6. 2.Inversion : Follows SN2 Mechanism. Isomer gets converted to other
form.
R isomer  S isomer
S isomer R isomer

7. 3.) Racemisation : Second chiral center forms Diasteromer (SS ,
RS)
R isomer  RR, RS isomer
S isomer  RS , SS isomer

8. Syllabus

9. Thank you my dear
students...!!!!!!