This document discusses the concepts of chirality and prochirality. Chirality refers to molecules that have mirror images that are not superimposable, often involving a carbon bonded to four different groups. Prochirality refers to molecules that can be converted from achiral to chiral in a single step. Chirality and prochirality are important concepts in stereochemistry and biochemistry, as most biologically relevant molecules like carbohydrates, proteins, and nucleic acids are chiral.

1. Concept of chirality,
prochirality
Done by
K.REVATHI 20-MY-14,
NGM COLLEGE,
POLLACHI.

2. Concept of chirality
 A molecule is chiral if its two mirror image forms not
superimposable in three dimensions.
 The word chiral is derived from the Greek word cheir
meaning, meaning “hand”.
 Chirality most often occurs in molecules that contain a carbon
that is attached to four different groups.

6. How do you determine chirality
• Look for carbons with four different groups attached to
identify potential chiral centres.
• Draw your molecules with wedges and dashes and then draw
a mirror image is the same molecule, it is achiral.
• If they are different molecules, then it is chiral.

7. Importance of chirality
• Chirality is the important concept of stereochemistry and
biochemistry.
• Most of the substances relevant to biology are chiral, such as
carbohydrates(sugars, starch and cellulose) the amino acids that
are the building blocks of proteins, and the nuclei acids.

8. prochirality
• In stereochemistry, prochiral molecules are those
that can be converted from achiral to chiral in a
single step.
• An achiral species which can be converted to a
chiral in two steps is called prochirality.

9. Example

10. How do you determine prochirality
• These faces are designated by the terms re and Si. To determine
which is the re and Si face of planar organic compounds.
• re is clockwise and Si is counter clockwise.

11. Importance of prochirality
• Prochirality is an important concept in biological chemistry,
because enzymes can distinguish between the two “identical”
groups bound to a prochiral carbon centre due to the fact
that they occupy different regions in three dimensional
space.

12. Are you feel boring….

15. chirality

17. Molecule

19. Carbon

21. Isomer

23. Carbohydrate

25. Protein

27. Prochirality

29. Three dimensional space