optical isomerism

• What is optical isomerism a form of?

  Stereoisomerism
• What distinguishes optical isomers from each other?

  A different arrangement of atoms in space
• What is a chiral carbon?

  A carbon atom with four different groups attached to it
• What are enantiomers?

  Optical isomers that are non-superimposable mirror images of each other
• What does it mean for enantiomers to be non-superimposable?

  They cannot be perfectly aligned on top of each other
• What is the significance of a mirror line in optical isomerism?

  It shows the relationship between two enantiomers
• How do you identify a chiral center in a molecule?

  By finding a carbon atom with four different groups attached
• What shape should be used to represent a chiral center in 3D?

  Tetrahedral shape
• What is plane polarized light?

  Light that oscillates in only one direction
• How does a chiral compound affect plane polarized light?

  It rotates the plane polarized light
• What happens when you have equal amounts of two enantiomers?

  You get a racemic mixture that does not rotate plane polarized light
• What is a racemic mixture?

  An equal mixture of two enantiomers
• Why is it important to note that a sample does not rotate plane polarized light?

  It does not necessarily mean there are no chiral centers present
• What are the key characteristics of optical isomers?

  • Same structural formula
  • Different arrangement of atoms in space
  • Non-superimposable mirror images
  • Presence of a chiral carbon with four different groups
• What are the steps to identify a chiral center in a molecule?

  1. Locate the carbon atom in the molecule.
  2. Check for four different groups attached to the carbon.
  3. Draw the molecule in a tetrahedral 3D shape.
  4. Represent the molecule as enantiomers with a mirror line.
• What is formed when there is an equal amount of each enantiomer in a mixture?

  Racemic mixture
• Why do racemic mixtures not rotate plane polarized light?

  Because the equal amounts of each enantiomer rotate light in opposite directions, canceling each other out
• What should you be cautious about when observing a sample that does not rotate plane polarized light?

  It may still contain optically active compounds
• How can a racemic mixture of a chiral product be formed?

  By reacting two non-chiral substances together
• What happens when an alkene reacts with a halogen like bromine?

  It can form a chiral compound if the resulting carbon has four different groups attached
• What is the significance of the thalidomide case in drug development?

  One enantiomer was effective for morning sickness while the other caused severe deformities
• Why is it important to consider the effects of both enantiomers in pharmaceuticals?

  Because one enantiomer may have therapeutic effects while the other may cause harmful side effects
• What is the role of cost-benefit analysis in drug development?

  To determine if the benefits of a drug justify its development costs
• What types of functional groups can lead to racemic products?

  C=C double bonds and C=O carbonyl groups
• How does the attack of a nucleophile on a carbonyl group lead to the formation of enantiomers?

  The nucleophile can attack from either side of the planar carbonyl group, leading to two different enantiomers
• What is the relationship between the symmetry of a ketone or aldehyde and the formation of enantiomers?

  Unsymmetrical ketones or aldehydes can lead to the formation of enantiomers due to their planar structure
• What does it mean for a reaction to produce a racemic mixture?

  It means that both enantiomers are produced in equal amounts
• What is the significance of the mirror images of enantiomers?

  They are non-superimposable and represent different spatial arrangements of atoms
• What are the key terms related to optical isomerism that students should know for exams?

  • Racemic mixture
  • Enantiomers
  • Chiral center
  • Plane polarized light
  • Nucleophile
• What are the steps involved in the formation of a racemic mixture from a reaction involving a carbonyl group?

  1. Nucleophile attacks the planar carbonyl group.
  2. Attack can occur from above or below.
  3. Two different enantiomers are formed.
  4. Equal chances lead to a racemic mixture.
• What are the implications of having both enantiomers in a pharmaceutical drug?

  • One enantiomer may be therapeutic.
  • The other may cause side effects.
  • Cost-benefit analysis is crucial for drug development.
  • Regulatory considerations for safety and efficacy.