Entrance Exams
Govt. Exams
PCC (Pyridinium chlorochromate) selectively oxidizes primary alcohols to aldehydes without further oxidation, and doesn't affect C=C.
Clemmensen reduction uses zinc amalgam with concentrated HCl to convert C=O to CH2, unlike Wolff-Kishner which uses hydrazine.
Grignard reagent attacks CO2 to form a salt, which upon hydrolysis gives benzoic acid.
The lone pair on nitrogen of aniline is more nucleophilic than the π electrons of benzene, making N-acylation the dominant pathway.
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.