Govt Exams
AlCl3 is the standard Lewis acid catalyst for Friedel-Crafts alkylation. It activates the alkyl halide to form a carbocation, which then attacks the aromatic ring.
The Wittig reaction uses a phosphonium ylide to convert carbonyl compounds (aldehydes and ketones) to alkenes. It's valuable for forming C=C double bonds with defined positions.
This is the hydration of alkynes using Hg2+ catalyst. Acetylene (HC≡CH) undergoes hydration to form acetaldehyde (CH3CHO) via enol intermediate, which tautomerizes.
As alkyl chain length increases, the electron-donating effect of the alkyl group increases, destabilizing the conjugate base carboxylate ion. Thus, formic acid (no alkyl group) is most acidic.
SN2 is a one-step bimolecular mechanism where the nucleophile attacks from the back side of the carbon bearing the leaving group, resulting in complete (Walden) inversion of configuration.
K2Cr2O7 in acidic medium is a strong oxidizing agent that oxidizes primary alcohols first to aldehydes, then further oxidizes the aldehyde to carboxylic acids.
Cold dilute KMnO4 causes hydroxylation of alkenes to form vicinal diols via syn addition. 2-methylpropene forms 2-methylpropane-1,2-diol (geminal diol arrangement on same carbon after rearrangement).
hex-3-ene (CH3CH2CH=CHCH2CH3) has different groups on each carbon of the double bond, allowing cis-trans (E-Z) isomerism. Cyclohexane and alkanes have no double bonds, and 2-methylpent-2-ene is not a correct formula for C6H12.
Hydroboration-oxidation follows anti-Markovnikov's rule with syn addition. The OH adds to the less substituted carbon (primary), giving 1-butanol (butan-1-ol).
Aldol condensation produces a β-hydroxy carbonyl compound (aldol) initially, which can further dehydrate under heating to form an α,β-unsaturated carbonyl compound.