Organic chemistry practice problems
Practice problems with answers for organic chemistry 1 and 2, for your exam and your degree: starting material and reagent given, which product forms? Plus one multi-step synthesis problem. Five problems, new every day, with structures and explanations. Free and without an account.
Keep practising for free, with your progress
The basic reactions without a daily limit in a free account. From €4.99 once or with Plus, all 157 reactions, over 1,500 syntheses, SN1/SN2/E1/E2 and exam mode.
What you can practise here
- ReactionsStarting material + reagent → product, or find the right reagent
- SynthesesFrom A to B in 2–3 steps: reagent sequence, intermediate and end product
- SN1/SN2/E1/E2NewSubstrate, reagent, conditions: which mechanism wins, with reasons
- Exam modeNew20 mixed tasks in 30 minutes, then results per topic
- MechanismsStep by step for every reaction, with typical exam mistakes
- Protecting groupsBoc, Fmoc, Cbz, TBS: when to put them on and take them off
Which main product forms?
Topics157 reactions with mechanisms, plus protecting groups and biomolecules
Nucleophilic substitution
- SN2 with hydroxide
- SN2 with cyanide (chain extension)
- SN2 with ammonia
- Williamson ether synthesis
- SN1 (hydrolysis)
- SN1 (solvolysis in ethanol)
- Finkelstein reaction
- Radical bromination of alkanes
- SN2 with azide
- Epoxide opening under basic conditions
- Epoxide opening under acidic conditions
- Ether cleavage with HI
Elimination
Alkenes & alkynes
- Addition of HBr (Markovnikov)
- Radical addition of HBr (anti-Markovnikov)
- Acid-catalysed hydration
- Hydroboration–oxidation
- Addition of bromine
- Catalytic hydrogenation
- Epoxidation
- syn dihydroxylation
- Ozonolysis (reductive work-up)
- Hydration of alkynes
- Halohydrin formation
- Oxymercuration–demercuration
- anti dihydroxylation
- Simmons–Smith cyclopropanation
- Addition of dichlorocarbene
- Ozonolysis (oxidative work-up)
- Allylic bromination
- Lindlar hydrogenation (cis alkene)
- Dissolving-metal reduction of alkynes (trans alkene)
- Alkylation of acetylides
- Hydroboration of alkynes
- Addition of HBr to alkynes
- Addition of bromine to alkynes
- HBr addition with carbocation rearrangement
Alcohols
Carbonyl chemistry
- Reduction with sodium borohydride
- Reduction with lithium aluminium hydride
- Grignard reaction
- Wittig reaction
- Imine formation
- Acetal formation (protecting group)
- Cyanohydrin formation
- Aldol addition
- Aldol condensation
- Oxidation of aldehydes (Tollens test)
- Wolff–Kishner reduction
- Clemmensen reduction
- Grignard reaction with phenylmagnesium bromide
- Carboxylic acid from Grignard and CO₂
- Ketone from a nitrile and Grignard
- Enamine formation
- Baeyer–Villiger oxidation
- Haloform reaction (iodoform test)
- 1,4-addition with cuprates (Gilman)
- Cannizzaro reaction
- Claisen–Schmidt condensation
- Acetal hydrolysis
- Oxime formation
- Fehling's test
- Luche reduction (1,2-reduction of enones)
- Horner–Wadsworth–Emmons reaction
Enolates & condensations
- Michael addition
- Robinson annulation
- Claisen condensation
- Dieckmann condensation
- Malonic ester synthesis
- Acetoacetic ester synthesis
- Alkylation with LDA (kinetic enolate)
- α-Bromination of ketones (acidic)
- Hell–Volhard–Zelinsky reaction
- Mannich reaction
- Decarboxylation of β-keto acids
- Intramolecular aldol condensation
- Benzoin condensation
- Knoevenagel condensation (Doebner)
Carboxylic acids & derivatives
- Acyl chloride from carboxylic acid
- Fischer esterification
- Ester hydrolysis (saponification)
- Amide from acyl chloride
- Ester from acyl chloride
- Acidic hydrolysis of amides and nitriles
- Acylation of amines
- Reduction with DIBAL-H
- Transesterification
- Esterification with acetic anhydride
- Beckmann rearrangement
- Ketone from acid chloride and cuprate
Amines
Aromatic compounds
- Nitration (SEAr)
- Aromatic bromination (SEAr)
- Friedel–Crafts acylation
- Reduction of nitroarenes
- Side-chain oxidation
- Benzylic bromination
- Sulfonation (SEAr)
- Friedel–Crafts alkylation
- Aromatic chlorination (SEAr)
- Sandmeyer reaction (chloride)
- Sandmeyer reaction (bromide)
- Sandmeyer reaction (nitrile)
- Phenol from a diazonium salt
- Aryl iodide from a diazonium salt
- Removing the amino group (H₃PO₂)
- Schiemann reaction (fluoride)
- Birch reduction
- Nucleophilic aromatic substitution (SNAr)
- Bromination of phenol
- Aryl ether (Williamson with phenoxide)
- Oxidation of hydroquinone to quinone
- Azo coupling
Heterocycles
- Paal–Knorr synthesis (pyrrole)
- Paal–Knorr synthesis (furan)
- Paal–Knorr synthesis (thiophene)
- Acylation of furan, thiophene and pyrrole
- Vilsmeier–Haack formylation
- Electrophilic substitution of pyridine
- Chichibabin reaction
- Nucleophilic substitution of halopyridines
- Pyridine N-oxide
- N-alkylation of pyridine
- Fischer indole synthesis
Pericyclic reactions
Carbohydrates
Amino acids & peptides
Polymersto read
Fats & lipidsto read
Nucleic acidsto read
How the trainer works
Verified chemistry, not AI guesses
Every reaction is stored as a rule and applied to many molecules by the chemistry software RDKit. The right products are computed, not made up by an AI.
Typical mistakes as answer options
The wrong answers are the classic exam mistakes: Markovnikov instead of anti-Markovnikov, elimination instead of substitution, over-oxidation, meta instead of para.
Practise weak spots
With an account the trainer remembers which reaction types you find hard and brings them back more often until they stick.
Common questions
Which topics does the trainer cover?
157 reactions from organic chemistry 1 and 2: nucleophilic substitution (SN1, SN2), elimination (E1, E2), additions to alkenes and alkynes, alcohols, carbonyl chemistry, enolates and condensations, carboxylic acid derivatives, amines, aromatic substitution, heterocycles, pericyclic reactions, carbohydrates and amino acids. Every reaction has its own page with the mechanism and typical mistakes.
How do I best practise for an organic chemistry exam?
Recall instead of rereading: look at the starting material and reagent, work out the product yourself, then check. A few problems every day work better than long sessions just before the exam. Watch the classic traps: regioselectivity (Markovnikov), substitution versus elimination and how far an oxidation goes.
Are the answers correct?
The products are not written by an AI. Every reaction is stored as a rule and the chemistry software RDKit computes the product for each molecule. The wrong options are typical exam mistakes, so you learn to spot them.
Is it free?
Yes. Five new problems every day without an account. A free account adds the basic reactions without a daily limit, with your progress. Plus adds all reactions, syntheses, SN1/SN2/E1/E2, exam mode and the AI tutor.