Term
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Definition
| aka constitutional isomers - same molecular formula but doesn't have to have same bonding or chemical or physical properties |
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Term
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Definition
| share the same structural backbone but differ in how the atoms are arranged in space |
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Term
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Definition
| differ by rotation around a single (σ) bond |
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Term
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Definition
| can only be interchanged by breaking and reforming bonds; E/Z molecules are configurational |
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Term
| What are the types of conformations in Newman projections? |
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Definition
- staggered - no overlap of atoms; there is anti (two largest group are on opposite sides) and gauche (two largest groups are 60o apart; right next to each other but not on top)
- eclipsed - two largest groups are 120o apart and overlap with smaller groups
- totally eclipsed - 0o separation between two largest groups; least energetically favorable
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Term
| What are the factors that cause ring strain? |
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Definition
- angle strain - created by stretching or compressing angles from their normal size
- torsional strain - from eclipsing conformations
- nonbonded strain - from interactions between substituents attached to nonadjacent carbons
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Term
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Definition
| atoms coming off of cyclohexane that stick up or down from the plane |
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Term
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Definition
| those atoms on cyclohexane that stick out (are parallel) to the plane of cyclohexane; larger group goes in equatorial position |
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Term
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Definition
| two molecules that are nonsuperimposable mirror images; they differ in rotation at every chiral carbon |
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Term
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Definition
| chiral molecules that differ at some but not all of their multiple chiral centers |
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Term
How is a compound named if it rotates light clockwise?
counterclockwise? |
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Definition
dextrorotatory (d) and (+)
levorotatory (l) and (-) |
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Term
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Definition
| has equal concetrations of two enantiomers, will not be optically active because the two enantiomers' rotations cancel each other other |
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Term
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Definition
| compound with an internal plane of symmetry, will be optically inactive because the two sides of the molecule cancel each other out; planes of symmetry can be through chiral carbons or between them |
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Term
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Definition
| number the atoms bonded to the carbon by highest to lowest priority; if the lowest priority group isn't at the back switch it with the group at the back; make a circle from highest to lowest priority, if it is clockwise then the molecule is R, counterclockwise S; if you had to switch the lowest priority group to the back then flip the configuration |
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Term
| determining configuration Fischer projections |
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Definition
- number the constituents bound to the carbon and determine R or S
- if the lowest priority group is pointing to the side, and thus out of the page, flip the configuration
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Term
| What are the placement rules for substituents on cyclohexane in a chair conformation? |
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Definition
cis-1,2; cis-1,4 axial-equatorial
cis-1,3 equatorial-equatorial
trans-1,2; trans-1,4 equatorial-equatorial
trans-1,3 axial-equatorial |
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