Chem 334 - Fall 1999
Organic Chemistry I

Dr. Carl C. Wamser

Chapter 4 Notes: Stereochemistry

Stereochemistry

Enantiomers

Enantiomer Examples






Chirality

Stereogenic Centers

Identifying Chiral Molecules


Properties of Enantiomers

Optical Activity

Specific Rotation

Absolute Configuration

R and S Designations

Right- and Left-Hand Views

Drawing 3-D Structures

Fischer Projections

Multiple Stereogenic Centers

Diastereomers

Meso Compounds

Identifying Meso Compounds

Cyclohexane Derivatives

Configurations and Conformations of Disubstituted Cyclohexanes

substitution

cis

trans

1,2-X2

eq,ax <==> ax,eq
(R,S)
interconverting enantiomers

eq,eq <==> ax,ax
(R,R) & (S,S)
isolable enantiomers
two conformations each

 1,2-XY

 eq,ax <==> ax,eq
isolable enantiomers
two conformations each

 eq,eq <==> ax,ax
isolable enantiomers
two conformations each

1,3-X2

eq,eq <==> ax,ax
(R,S) - meso compound
two conformations

eq,ax <==> ax,eq
isolable enantiomers
two conformations each

 1,3-XY

 eq,eq <==> ax,ax
isolable enantiomers
two conformations each

 eq,ax <==> ax,eq
isolable enantiomers
two conformations each

 1,4-X2
no stereocenters

 eq,ax <==> ax,eq
equivalent conformations

 eq,eq <==> ax,ax
two conformations

1,4-XY
no stereocenters

eq,ax <==> ax,eq
two conformations

eq,eq <==> ax,ax
two conformations

Racemic Mixtures

Optical Purity / Enantiomeric Excess

Optical Resolution

Isomerism - Summary

Stereoisomers - Summary