To prevent one of these intermediates from rearranging during a Friedel–Crafts alkyl·ation, you can perform an acyl·ation instead and then reduce the ketone. For 10 points each:
[10m] Name these intermediates formed under acid catalysis that rearrange via hydride or methanide shifts.
ANSWER: carbo·cat·ions [or carbenium or carbonium ions; accept arenium ions or Wheland intermediates; prompt on cations or ions]
[10e] Carbo·cat·ions rearrange to let this atomic orbital on the carbon accept electrons from nearby pi or sigma-star orbitals. A carbocation’s bonding orbitals are hybridized from one s orbital and two of these atomic orbitals.
ANSWER: p orbitals [accept 2p orbitals]
[10h] Unlike in carbocations, the [emphasize] more substituted alkyl group shifts to an electron-deficient oxygen in the concerted final step of this named reaction. Migratory aptitude is often taught in the classroom in the context of this reaction.
ANSWER: Baeyer–Villiger reaction [or Baeyer–Villiger oxidation; or Baeyer–Villiger rearrangement; or BV oxidation]
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