Orgo Ch 5 Pt. 2

  1. Stereoisomers are?
    examples: __
    • same atoms connected to same atoms pointing in opposite directions
    • cis-trans
  2. Stereoisomers can be divided into what?
    • enantiomers (mirror images are not superimposable)
    • diastereomers (not mirror images; different physical properties; way different)
  3. Properties of enantiomers
    same physical properties; identical with exception of smell and direction of optical rotation
  4. Presence of what gives rise to ability to form enantiomers?
    What does it form?
    • asymmetric center called chiral atoms
    • chiral compounds
  5. Asymmetric center doesn't have to be __, but usually is. 
    In order to have a chiral center, what must you have?
    • Carbon
    • four different groups bonded to the carbon
  6. Chiral compounds and optical rotation?
    will rotate in plain, polarized light
  7. Polarized light is what?
    • waves are all synchronous; all coming at you
    • plain polarized light will bind in a chiral compound
  8. True or False: 
    Not all tetrahedrals are chiral centers, but those with four different groups are.
    True
  9. True or False:
    You can only have one chiral center.
    False: you can have more than one
  10. If you have one asymmetric carbon, you have __ stereoisomers.
    Two?
    Three?
    What is the trend
    • 2
    • 4
    • 8 2^n
  11. Stereocenters
    any atom where interchange of any two groups gives you a stereoisomer
  12. Achiral compounds have what?
    an internal plane of symmetry
  13. True or False:
    Having a chiral center means you're chiral.
    False: you can have a chiral center, but still have an achiral compound
  14. The presence of a chiral center does not necessitate __ or __.
    • optical rotation
    • chiral compounds
  15. Cyclohexanes
    What can we say about them?
    they switch chair conformations alot
  16. Trans compounds will have what?
    a plane of symmetry
  17. Relationship between R and S and + and -
    nothing
  18. If you have two chiral centers, what R and S configs can you have?
    • RR
    • RS
    • SS
    • SR
  19. Complexity arises when what?
    • groups aren't halogens
    • - rules develop
  20. Absolute configuration
    term used to ask "is it R or is it S"
  21. Can chiral centers exist in rings?
    yes
  22. When you have a tie and you look at the second bonded group, what can you do?
    stop once the first atom differs; who cares if its a bigger molecule
Author
DesLee26
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241571
Card Set
Orgo Ch 5 Pt. 2
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