Packet C: Bonus 8
A modification of this reaction typically uses a cyclic amine to catalyze the nucleophilic addition of an activated methylene into a carbonyl and was discovered by Emil Knoevenagel (“kuh-NO-vuh-NAH-gul”). For 10 points each:
[10m] Name this reaction described by the Zimmerman–Traxler model, which predicts that 1,3-allylic strain is minimized in its transition state. Unlike Claisen condensations, this reaction uses a ketone or aldehyde electrophile.
ANSWER: aldol reaction [or aldol condensation or aldol addition]
[10e] This property is maintained syn in aldol reactions according to the Zimmerman–Traxler model and can be controlled using Evans oxazolidinones (“ox-uh-ZO-lid-in-owns”). Compounds with this property cannot be superimposed on its mirror image.
ANSWER: chirality [or chiral; accept chiral auxiliaries; accept enantiomeric or enantioselectivity; prompt on stereometric or stereoselectivity; prompt on asymmetry or asymmetric induction; prompt on racemic; prompt on optical active or optical activity; prompt on isomerism]
[10h] The Zimmerman–Traxler model does not apply to Mukaiyama aldol reactions that use enol ethers of this functional group, which can be generated using the stereoretentive Brook rearrangement.
ANSWER: silyl groups [or silane groups; accept silyl ethers or silyl enol ethers; accept acylsilanes; accept trimethylsilyl groups or TMS groups; accept triethylsilyl groups or TES groups or tert-butyldimethylsilyl groups or TBS groups; prompt on organosilicon groups]
<Virginia Tech A, Chemistry> | Packet C - Virginia Tech A, Waterloo A, UCSD A, UBC A
| Heard | PPB | E % | M % | H % |
|---|---|---|---|---|
| 72 | 14.03 | 94% | 28% | 18% |
Conversion
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total | Parts |
|---|---|---|---|---|---|---|
| Columbia A | Vassar | 0 | 10 | 10 | 20 | EH |
| Columbia C | Maryland A | 0 | 10 | 0 | 10 | E |
| Johns Hopkins A | Columbia B | 0 | 10 | 10 | 20 | EH |
| Maryland B | John Jay | 0 | 10 | 0 | 10 | E |
| Maryland C | Georgetown | 0 | 10 | 0 | 10 | E |
| NYU A | Johns Hopkins B | 10 | 10 | 10 | 30 | MEH |
| NYU B | Catholic | 0 | 10 | 0 | 10 | E |
| Swarthmore | NYU C | 10 | 10 | 0 | 20 | ME |
Summary
| Tournament | Edition | Match | Heard | PPB | E % | M % | H % |
|---|---|---|---|---|---|---|---|
| California (North) | Main Site | ✓ | 3 | 13.33 | 67% | 67% | 0% |
| Canada | Main Site | ✓ | 10 | 13.00 | 90% | 20% | 20% |
| Florida | Main Site | ✓ | 3 | 16.67 | 100% | 67% | 0% |
| Great Lakes | Main Site | ✓ | 5 | 14.00 | 100% | 20% | 20% |
| Midwest | Main Site | ✓ | 8 | 12.50 | 75% | 25% | 25% |
| Northeast | Main Site | ✓ | 6 | 18.33 | 100% | 50% | 33% |
| Overflow | Main Site | ✓ | 4 | 10.00 | 100% | 0% | 0% |
| South Central | Main Site | ✓ | 2 | 15.00 | 100% | 50% | 0% |
| Southeast | Main Site | ✓ | 7 | 14.29 | 100% | 29% | 14% |
| UK | Main Site | ✓ | 12 | 13.33 | 100% | 25% | 8% |
| Upper Mid-Atlantic | Main Site | ✓ | 8 | 16.25 | 100% | 25% | 38% |
| Upstate NY | Main Site | ✓ | 4 | 12.50 | 100% | 0% | 25% |