Govt. Exams
Entrance Exams
Methoxy group is ortho-para directing and activating. Due to steric hindrance at para position, 2-nitroanisole is the major product.
Iodoform test requires either a methyl ketone (COCH3) or secondary alcohol with CH3 adjacent to CHOH. Ethanol has no such structure.
Phenoxide ion is stabilized by resonance with the benzene ring, making phenol more acidic than aliphatic alcohols.
Primary carbocation rearranges via hydride shift to form more stable secondary carbocation, which then forms isopropylbenzene.
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).
