Kaplan Organic Chemistry Chapter 2

Card Set Information

Kaplan Organic Chemistry Chapter 2
2015-01-31 14:03:40

Show Answers:

  1. structural isomers/constitutional isomers
    same molecular formula
  2. stereoisomers
    share the same atomic connectivity
  3. conformational isomers
    differ in rotation around single bonds
  4. configurational isomers
    interconverted only by breaking bonds
  5. anti-conformation
    two largest groups are antiperiplanar (opposite sides)
  6. staggered conformation
    no overlap of atoms along the line of sight, opposite of eclipsed
  7. what is the most stable conformation of cyclohexane?
    chair conformation where two equatorial methyl groups are trans to each other.
  8. does enantiomers have identical physical and chemical properties
    yes except for optical acitivity and reactions in chiral environments
  9. optical activity
    refers to the rotation of plane-polarized light by a chiral molecule.
  10. specific rotation
    • standardized units for comparison purposes
    • equals observed rotation in degrees divided by concentration (g/ml) and path length
  11. racemic mixture
    equal amounts of both enantiomers, no optical activity.
  12. diastereomers
    • non-mirror images
    • molecule has two or more stereogenic centers and differs at some, but not all of these centers.
  13. for molecule with n stereocenters, how many possible stereoisomers?
  14. differences between diastereomers and enantiomers
    • diastereomers have diff chem properties
    • rotate plane-polarized light but the magnitude is not equal and opposite to another diastereomer
  15. cis-trans/geometric isomers
    substituents differ in position around an immovable bond
  16. E and Z forms
    used for compounds with polysubstituted double bond
  17. cahn ingold prelog priority rules
    • based on atom bound to double bond (E/Z)
    • higher the atomic number, more priority
  18. what does horizontal and vertical lines represent in Fischer projection
    • horizontal lines (pointing out)
    • vertical lines (bonds going into the page)
  19. assigning R and S
    any time two groups are switched on a chiral carbon, the stereochemistry is inverted.
  20. what changes the absolute conformation?
    when reactant and product has different stereochemistry (R to S)
  21. relative configuration
    stays the same when bonds of stereocenter are not broken, when positions of chiral carbons are maintained.
  22. can E and Z be diastereomers?
    yes b/c they have the same connectivity