1. Chirality Chapter 4, 5, & 6

2. Isomers Same Molecular Formula
Constitutional - Differing in order of attachment
Stereoisomers - Same order of attachment, differing in orientation
Enantiomers - Mirror images
Diasteriomers - Not mirror images

3. Fig 4.1

4. Constitutional Isomers
Different compounds with the same molecular formula
Constitutional Isomers
Isomers with a different order of attachment of atoms in their molecule

5. Stereoisomers
Isomers with the same order of attachment of atoms in their molecules, but a different orientation of their atoms or groups of atoms in space
Maximum number of Isomers = n2 where n = the number of stereocenters

6. Enantiomers
Stereoisomers whose molecules are mirror images of each other

7. Diasteriomers
Stereoisomers whose molecules are not mirror images of each other.

8. R,S System Priority Rules 1. Priority on Atomic Number
H<BR2<-CH3<-NH2,-OH<-SH<-Cl<-Br
2. Ties go to Next Atom
CH2-Q
3. Double & Triple like self but multiples
C=CH2, -CCH

9. Examples and Problems

10. More on Priority -CH=CH2 treated as-CC-CCH2 -CCH treated as -CCC-CCCH
-CO2H treated as -C(OH)(OC)
-CHO treated as -C(OC)(O)H
-CN treated as -C(NN)(NCC)

11. Rules Top-Bottom always point out Sideways always point back
Assign highest to lowest
Rotate smallest to back-always flips its pair
Read from Highest to 2nd lowest
Right R; Left S

12. Examples

13. Acyclic
Figure 6.8 & 6.9

14. Example

15. Meso An Achrial compound processing 2 or more stereocenters
Molecule has one or more planes of symmetry.
Example

16. Cyclics
Cis and Trans for geometric designation
then apply R,S

17. Example

18. Properties specific rotation 180º different
all others same, mp. Bp, density, spectroscopic
example

19. Fig4.7

20. Polarimetery
Figure 4.6

21. Equation Specific Rotation = [] [] = Observed rotation(°)
Length(dm) x Concentration(g/mL)

22. Resolution
salt formation

23. Reactions that Produce Chiral Compounds Chapter 6.6
Anti Addition Mechanism #3
Br2 + cis-2- butene 2 products
Br2 + trans-2- butene 1 products
Syn Addition
Cis -meso
Trans pair of enantioners

24. Examples

25. Biological Usefulness of Chirality