Ochem 2012 Review Guides.pdf
O-Chem Day 2 – Isomers, Newman Projections, Cycloalkanes, Substitution, Elimination
Chiral compounds have non-superimposable (non-identical) mirror images called enantiomers.
Achiral compounds have mirror images that are superimposable (identical).
Chiral compounds are said to be optically active.
A 50/50 mixture of enantiomers is called a racemic mixture and is optically inactive.
Chirality centers are tetrahedral centers with four different substituents (i.e. asymmetric centers).
R vs. S
Multiple chiral centers
Meso compounds (achiral but having chiral centers)
Chiral molecules with no chiral centers
Staggered, eclipsed, anti, gauche
Chair Conformations of Cyclohexane
Equatorial positions are lower in energy (i.e. more stable) than axial positions due to 1,3-diaxial interactions