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]
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