🧬 Organic Chemistry
148 chemistry topics in Organic Chemistry, from beginner to intermediate to advanced level. Each topic has a clear explanation, a worked example, frequently asked questions and an interactive lesson.
Beginner topics in Organic Chemistry (26)
- Organic ChemistryThe study of carbon-containing compounds, which form the basis of life and many materials.
- Tetravalency of CarbonCarbon forms four bonds, allowing chains, rings and enormous molecular diversity.
- CatenationThe ability of carbon atoms to link with one another in long chains and rings.
- Functional GroupsSpecific atoms or groups that determine the characteristic reactions of a molecule.
- Homologous SeriesA family of compounds with the same functional group differing by a CH2 unit.
- AlkanesSaturated hydrocarbons with only single bonds and the formula CnH2n+2.
- AlkenesHydrocarbons containing a carbon-carbon double bond with formula CnH2n.
- AlkynesHydrocarbons containing a carbon-carbon triple bond with formula CnH2n-2.
- Aromatic HydrocarbonsCompounds containing benzene-like rings with delocalized pi electrons.
- IUPAC NomenclatureSystematic rules for naming organic compounds by longest chain, substituents and…
- Structural IsomerismCompounds with the same molecular formula but different connectivity of atoms.
- Chain IsomerismIsomers differ in the branching of the carbon skeleton.
- Position IsomerismIsomers differ in the position of the functional group or substituent.
- Electrophiles and NucleophilesElectrophiles seek electrons while nucleophiles donate electron pairs.
- Reaction Types in Organic ChemistrySubstitution, addition, elimination and rearrangement reactions are the main classes.
- Combustion of HydrocarbonsHydrocarbons burn in oxygen to give carbon dioxide and water, releasing energy.
- Fractional Distillation of Crude OilCrude oil is separated into fractions by boiling point range.
- AlcoholsCompounds with an OH group bonded to saturated carbon, classified as primary, secondary…
- Properties of AlcoholsHydrogen bonding gives alcohols higher boiling points and water solubility than similar…
- Ethanol ProductionMade by fermentation of sugars or hydration of ethene.
- AldehydesCompounds with a terminal carbonyl group, easily oxidized to carboxylic acids.
- KetonesCompounds with a carbonyl group between two carbons.
- Carboxylic AcidsCompounds with COOH group, weak acids with strong hydrogen bonding.
- EstersCompounds from acid and alcohol condensation with fruity smells.
- Soaps and DetergentsCleaning agents with hydrophilic heads and hydrophobic tails that emulsify oils.
- Polymers OverviewLarge molecules made by linking many repeating monomer units.
Intermediate topics in Organic Chemistry (56)
- CycloalkanesSaturated hydrocarbons with carbon atoms joined in a ring.
- Functional Group IsomerismIsomers with the same formula but different functional groups, such as ethanol and…
- StereoisomerismIsomers with same connectivity but different spatial arrangement.
- Cis-Trans IsomerismGeometric isomerism arising from restricted rotation about a double bond or ring.
- ChiralityA molecule that is non-superimposable on its mirror image, usually due to a carbon with…
- EnantiomersMirror-image stereoisomers that rotate plane-polarized light in opposite directions.
- Optical ActivityThe ability of chiral compounds to rotate plane-polarized light.
- ConformationsDifferent spatial arrangements arising from rotation about single bonds.
- Newman ProjectionsViews along a C-C bond showing staggered and eclipsed conformations.
- Inductive EffectPermanent polarization of sigma bonds due to electronegativity differences.
- Resonance EffectDelocalization of pi electrons affecting stability and reactivity.
- Free RadicalsSpecies with an unpaired electron formed by homolytic bond cleavage.
- CarbocationsPositively charged carbon species whose stability is tertiary above secondary above…
- CarbanionsNegatively charged carbon species stabilized by electron-withdrawing groups.
- Homolytic and Heterolytic FissionBond breaking that splits electrons evenly into radicals or unevenly into ions.
- Free Radical HalogenationAlkanes react with halogens under light via initiation, propagation and termination steps.
- CrackingBreaking long hydrocarbons into shorter alkanes and alkenes using heat or catalysts.
- Octane NumberA measure of a fuel's resistance to knocking in engines.
- Electrophilic AdditionAlkenes react with electrophiles such as HBr, adding across the double bond.
- Markovnikov's RuleIn addition of HX to alkenes, hydrogen adds to the carbon with more hydrogens already.
- HydrogenationAddition of H2 across multiple bonds using metal catalysts.
- Hydration of AlkenesAcid-catalyzed addition of water to give alcohols.
- Polymerization of AlkenesAlkene monomers join to form long chains such as polyethylene.
- HaloalkanesAlkyl halides containing a carbon-halogen bond, useful in substitution reactions.
- Oxidation of AlcoholsPrimary alcohols oxidize to aldehydes and acids, secondary to ketones, tertiary resist.
- PhenolsCompounds with OH attached to an aromatic ring, more acidic than alcohols.
- EthersCompounds with an oxygen bonded to two carbons, relatively unreactive solvents.
- Tollens' TestSilver mirror forms with aldehydes, distinguishing them from ketones.
- Fehling's TestAldehydes reduce blue copper(II) to red copper(I) oxide.
- EsterificationAcid and alcohol react under acid catalysis to form ester and water.
- Hydrolysis of EstersEsters are cleaved by acid or base, with base hydrolysis called saponification.
- SaponificationAlkaline hydrolysis of fats producing soap and glycerol.
- AmidesCompounds with carbonyl bonded to nitrogen, stabilized by resonance and found in proteins.
- AminesOrganic derivatives of ammonia that act as bases and nucleophiles.
- Nitro CompoundsCompounds with NO2 group, important in explosives and dyes.
- Carbohydrate StructurePolyhydroxy aldehydes or ketones that include sugars, starch and cellulose.
- Amino AcidsMolecules with amine and carboxyl groups, the building blocks of proteins.
- ZwitterionsDipolar ions bearing both positive and negative charges, common for amino acids at…
- Peptide BondAn amide link between the carboxyl of one amino acid and the amine of another.
- LipidsFats, oils and related molecules insoluble in water, serving as energy stores and…
- Nucleic Acid StructureDNA and RNA are polymers of nucleotides containing sugar, phosphate and base.
- Addition PolymersFormed by chain addition of unsaturated monomers, such as polyethylene and PVC.
- Condensation PolymersFormed by joining monomers with elimination of small molecules, such as nylon and…
- Natural and Synthetic RubberPolyisoprene from latex and synthetic analogs; vulcanization crosslinks chains with…
- Biodegradable PolymersPolymers such as PLA that microorganisms break down.
- Green Chemistry PrinciplesTwelve principles for reducing hazardous substances and waste in chemical design.
- PharmaceuticalsDrugs designed to interact with biological targets, such as aspirin and penicillin.
- Aspirin SynthesisAcetylation of salicylic acid with acetic anhydride gives acetylsalicylic acid.
- Dyes and PigmentsColored organic compounds with extended conjugated systems.
- PetrochemicalsChemicals derived from oil and gas used for plastics, solvents and fibers.
- Qualitative Organic TestsBromine water for unsaturation, 2,4-DNP for carbonyls and iodoform for methyl ketones.
- Purification of Organic CompoundsDistillation, crystallization, sublimation and chromatography isolate pure compounds.
- ChromatographySeparation based on differing distribution between mobile and stationary phases.
- Elemental AnalysisDetermining percentages of C, H and N to find empirical formulas.
- Degree of UnsaturationA count of rings and pi bonds derived from molecular formula.
- Baeyer's ReagentCold dilute potassium permanganate tests for double bonds by decolorizing.
Advanced topics in Organic Chemistry (66)
- E-Z NotationA CIP priority-based system for naming alkene geometry.
- DiastereomersStereoisomers that are not mirror images of each other.
- Meso CompoundsCompounds with chiral centers that are achiral overall due to internal symmetry.
- Racemic MixtureAn equal mixture of two enantiomers showing no optical activity.
- CIP Priority RulesCahn-Ingold-Prelog rules assign R or S configuration using atomic number priorities.
- Fischer ProjectionsTwo-dimensional representation of stereochemistry of sugars and amino acids.
- Cyclohexane Chair ConformationThe strain-free chair form with axial and equatorial positions.
- Ring StrainInstability in small rings due to angle and torsional strain.
- HyperconjugationStabilization from interaction of sigma bonds with adjacent empty or pi orbitals.
- Electromeric EffectA temporary shift of pi electrons caused by an attacking reagent.
- CarbenesNeutral divalent carbon species with six valence electrons.
- Anti-Markovnikov AdditionIn the presence of peroxides, HBr adds via a radical mechanism with opposite…
- OzonolysisCleavage of alkenes with ozone to give carbonyl compounds.
- Electrophilic Aromatic SubstitutionBenzene reacts with electrophiles, replacing hydrogen while keeping aromaticity.
- Nitration of BenzeneReaction with nitric and sulfuric acid mixture gives nitrobenzene.
- Friedel-Crafts ReactionsAlkylation or acylation of arenes catalyzed by Lewis acids such as AlCl3.
- Directing EffectsSubstituents direct incoming groups to ortho, para or meta positions.
- SN1 ReactionA two-step unimolecular nucleophilic substitution through a carbocation, favoring…
- SN2 ReactionA one-step bimolecular substitution with backside attack and inversion of configuration.
- E1 EliminationA two-step elimination via carbocation giving alkenes.
- E2 EliminationA one-step bimolecular elimination requiring a strong base and anti-periplanar geometry.
- Zaitsev's RuleThe more substituted alkene is the major product of elimination.
- Lucas TestReagent distinguishing primary, secondary and tertiary alcohols by speed of turbidity.
- Williamson Ether SynthesisAn alkoxide reacts with an alkyl halide via SN2 to form an ether.
- Nucleophilic Addition to CarbonylsNucleophiles attack the electrophilic carbon of C=O groups.
- Aldol CondensationEnolates add to carbonyls forming beta-hydroxy carbonyls that dehydrate to enones.
- Cannizzaro ReactionAldehydes lacking alpha hydrogens disproportionate in strong base to alcohol and acid.
- Grignard ReagentsOrganomagnesium compounds that add to carbonyls to form new carbon-carbon bonds.
- Acid Chlorides and AnhydridesHighly reactive acid derivatives used for acylation.
- Basicity of AminesAlkyl groups raise basicity; aromatic amines are weaker bases due to delocalization.
- Diazonium SaltsReactive intermediates from aromatic amines used to make azo dyes.
- Hofmann DegradationConverts an amide into a primary amine with one fewer carbon.
- NitrilesCompounds with CN group, hydrolyzed to acids or reduced to amines.
- ThiolsSulfur analogs of alcohols with strong odors.
- Glucose Ring FormsGlucose cyclizes to alpha and beta pyranose forms through hemiacetal formation.
- Reducing SugarsSugars with free hemiacetal groups reduce Tollens' and Fehling's reagents.
- Organic Reaction MechanismsCurved arrows show electron movement during bond breaking and forming.
- RetrosynthesisPlanning a synthesis by working backward from the target molecule.
- Protecting GroupsTemporary modifications masking reactive functional groups during synthesis.
- Diels-Alder ReactionA [4+2] cycloaddition between a diene and dienophile forming cyclohexene rings.
- Wittig ReactionConverts aldehydes or ketones into alkenes using phosphorus ylides.
- Claisen CondensationEster enolate attacks another ester giving a beta-keto ester.
- Michael AdditionConjugate addition of nucleophiles to alpha,beta-unsaturated carbonyls.
- Pericyclic ReactionsConcerted reactions through cyclic transition states governed by orbital symmetry.
- Woodward-Hoffmann RulesRules predicting stereochemistry of pericyclic reactions from orbital symmetry.
- Cross-Coupling ReactionsPalladium-catalyzed reactions such as Suzuki and Heck forming carbon-carbon bonds.
- Olefin MetathesisCatalytic exchange of alkene substituents using ruthenium carbene catalysts.
- Asymmetric SynthesisMethods to make a single enantiomer using chiral catalysts or auxiliaries.
- Heterocyclic CompoundsRings containing atoms other than carbon, such as pyridine, furan and pyrrole.
- PyridineAn aromatic nitrogen heterocycle that is a weak base and widely used solvent.
- AlkaloidsNitrogen-containing natural products with pharmacological effects, such as caffeine and…
- TerpenesNatural products built from isoprene units, giving scents and flavors.
- SteroidsLipids with four fused rings including cholesterol and sex hormones.
- Iodoform ReactionMethyl ketones and ethanol give yellow iodoform precipitate with iodine and base.
- Acidity of Terminal AlkynesTerminal alkynes are weakly acidic and form acetylides with strong bases.
- Keto-Enol TautomerismInterconversion between carbonyl form and enol form, important in carbonyl reactivity.
- Alpha Hydrogen AcidityHydrogens next to carbonyls are acidic because the enolate is resonance stabilized.
- Williamson vs EliminationHindered alkyl halides favour elimination over substitution with strong bases.
- Reduction of CarbonylsHydride reagents such as NaBH4 and LiAlH4 reduce aldehydes and ketones to alcohols.
- EpoxidesStrained three-membered cyclic ethers that open readily with nucleophiles.
- Sharpless EpoxidationAn enantioselective epoxidation of allylic alcohols using titanium and tartrate.
- Hydroboration-OxidationAnti-Markovnikov syn hydration of alkenes using borane then peroxide.
- Baeyer-Villiger OxidationKetones are converted to esters by peracids.
- Beckmann RearrangementOximes rearrange into amides under acid conditions.
- Pinacol RearrangementVicinal diols rearrange to carbonyl compounds under acid.
- Wagner-Meerwein RearrangementCarbocation rearrangements involving alkyl or hydride shifts.
Frequently asked questions about Organic Chemistry
How many topics are in Organic Chemistry?
Organic Chemistry has 148 topics, from beginner to intermediate to advanced level.
Where should I start in Organic Chemistry?
Start with Organic Chemistry at the beginner level, then work through the topics in order.
Does every topic have an explanation and an example?
Yes. Each topic page has an in-depth explanation, a worked example, FAQs and links to related topics.