Organic Name Reactions: JEE Main Complete Guide

Organic name reactions account for approximately 4–6 marks per JEE Main session — questions that directly name a reaction and ask for the product, reagent, or mechanism. Mastering the 35–40 name reactions that appear in JEE Main requires understanding the mechanism (not just the product), knowing the reagent conditions, and recognising the structural features that trigger each reaction. This guide covers all JEE Main-relevant name reactions with mechanisms, key conditions, and the specific question formats NTA uses to test each one.

Carbonyl Chemistry Name Reactions

Aldol Condensation: an aldehyde or ketone with an alpha-hydrogen reacts with another carbonyl compound in dilute NaOH to give a beta-hydroxy carbonyl compound (aldol product), which on heating dehydrates to give an alpha-beta unsaturated carbonyl (aldol condensation product). Intramolecular aldol cyclises 6-membered rings readily. Cross aldol (between two different carbonyls) gives a mixture unless one reactant lacks alpha-H (e.g., benzaldehyde — use it as the electrophile with a ketone/aldehyde as nucleophile under specific conditions). Cannizzaro Reaction: aldehydes without alpha-H (HCHO, C6H5CHO, (CH3)3CCHO) undergo disproportionation in concentrated NaOH — one molecule is oxidised to the carboxylate salt, another is reduced to the alcohol. Mechanism: hydride transfer from the alkoxide intermediate. Cross-Cannizzaro: HCHO + benzaldehyde in NaOH → benzyl alcohol + sodium formate (HCHO is preferentially oxidised). These reactions are tested as product prediction questions in JEE Main. For the broader organic chemistry context, see our Organic Chemistry Reactions Guide.

Clemmensen Reduction: C=O of aldehyde/ketone → CH2 using Zn-Hg amalgam + concentrated HCl. Wolff-Kishner Reduction: same conversion using hydrazine (H2N-NH2) + KOH/ethylene glycol at high temperature. Both give the methylene product without affecting other functional groups (Clemmensen under acidic conditions, Wolff-Kishner under basic). JEE Main often asks: which reagent converts -CHO to -CH3? Answer: both Clemmensen and Wolff-Kishner. Which is suitable for an acid-sensitive substrate? Wolff-Kishner. Baeyer-Villiger Oxidation: ketone + peracid (mCPBA, H2O2/H+) → ester. The oxygen inserts adjacent to the more substituted carbon (migratory aptitude: tertiary greater than secondary greater than aryl greater than primary greater than methyl). Methyl ketone (RCOCH3) → ester (RCOOCH3) using peracid — this is the Baeyer-Villiger test directly tested in JEE.

Aromatic and Carbon-Carbon Bond Forming Reactions

Friedel-Crafts Alkylation: ArH + RCl + AlCl3 → Ar-R. Limitations: polyalkylation occurs (product is more reactive than reactant); carbocation rearrangement possible; does not work with deactivated rings (nitrobenzene fails). Friedel-Crafts Acylation: ArH + RCOCl + AlCl3 → Ar-COR. No rearrangement (acylium ion is stable and doesn't rearrange). Product is less reactive than reactant — no polyacylation. Grignard Reagent: RMgX (formed from R-X + Mg/dry ether). Reacts with: H2O → RH; HCHO → primary alcohol (RCH2OH); RCHO → secondary alcohol (RRCHOH); R2CO → tertiary alcohol; CO2 → carboxylic acid (RCOOH); epoxide → alcohol with ring opening; nitrile → ketone (after hydrolysis). Practise name reaction product prediction on our JEE Main chemistry mock tests with explanations tracing each step of the mechanism.

Kolbe Reaction: sodium phenoxide (C6H5ONa) + CO2 + pressure + heat → sodium salicylate (ortho-hydroxybenzoate salt). Subsequent acidification gives salicylic acid. This is the industrial synthesis of aspirin (acetylsalicylic acid from salicylic acid + acetic anhydride). Reimer-Tiemann Reaction: phenol + CHCl3 + NaOH → ortho-hydroxybenzaldehyde (salicylaldehyde). Mechanism involves dichlorocarbene (:CCl2) as the electrophile. JEE Main tests: Kolbe and Reimer-Tiemann as methods for introducing a substituent at the ortho position of phenol.

Reduction and Oxidation Name Reactions

Rosenmund Reduction: acid chloride (RCOCl) + H2 over Pd/BaSO4 (poisoned catalyst) → aldehyde (RCHO). Key condition: the BaSO4 poisoning prevents over-reduction to alcohol. Stephen Reduction: nitrile (RCN) + SnCl2/HCl, then hydrolysis → aldehyde (RCHO). Both Rosenmund and Stephen give aldehydes from different functional groups — JEE Main tests which starting material and reagent combination gives an aldehyde. Gabriel Synthesis: phthalimide + KOH + RX → N-alkyl phthalimide, then hydrazine/KOH → primary amine (RNH2). Limitation: only primary amines can be prepared. Useful when you need a pure primary amine without secondary or tertiary amine contamination. Hofmann Bromamide Reaction (Hofmann Degradation): amide (RCONH2) + Br2/NaOH → primary amine (RNH2) with one less carbon. The carbonyl carbon is lost as CO2. This is a chain-shortening reaction — a unique feature tested in JEE Main questions on amine synthesis.

Sandmeyer Reaction: ArN2+ (diazonium salt) + CuCN → ArCN; + CuCl → ArCl; + CuBr → ArBr. Balz-Schiemann Reaction: ArN2+ BF4- → ArF + N2 + BF3 (the only reliable route to aryl fluorides). Gattermann Reaction: ArH + CO + HCl + AlCl3 + CuCl → ArCHO. All three reactions go through diazonium chemistry — memorise the specific reagent combinations: Sandmeyer (Cu salt), Balz-Schiemann (fluoroborate), Gattermann (CO/AlCl3/CuCl). JEE Main tests: "which reaction converts aniline to fluorobenzene?" Answer: Balz-Schiemann (via diazotisation then fluoroborate treatment).

Synthesis and Multi-Step Problems

JEE Main increasingly includes questions where 2–3 name reactions appear in a synthetic sequence, and you must identify the intermediate or final product. These multi-step questions reward students who know how the product of one reaction feeds into the next. Example sequence: toluene → nitrotoluene (nitration) → toluidine (Fe/HCl reduction) → diazonium salt (NaNO2/HCl, 0–5°C) → phenol (warm water hydrolysis) → salicylic acid (Kolbe reaction). JEE Main may show steps 3–4 and ask you to identify the intermediate or the final product. Practice 20 such multi-step organic sequences from Arihant or NCERT Exemplar organic sections. Create an account to access our complete name reactions flashcard set and multi-step synthesis practice problems. Our premium subscription includes detailed mechanism videos for all 40 JEE-relevant name reactions. For the mechanisms that explain why these reactions work, see our Reaction Mechanisms Complete Guide.

Before the exam, create a one-page name reactions cheat sheet: reaction name | starting material | reagent/condition | product. This 40-row table takes 2 hours to build and provides your most efficient final-week revision tool for organic chemistry. Reviewing it for 20 minutes daily in the last 7 days essentially locks in 4–6 marks that would otherwise be lost to memory lapses.