An organic compound is a compound that contains carbon atoms, usually covalently bonded to hydrogen atoms and possibly other elements like oxygen, nitrogen, halogens, etc.

The main functional groups are alkyl halides, alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, amines, and amides.

Sigma (σ) bonds are formed by head-on overlap of atomic orbitals, while pi (π) bonds are formed by sideways overlap of p-orbitals, resulting in a delocalized electron cloud above and below the bonded atoms.

Resonance is the delocalization of electrons across multiple bonds in a molecule. It helps stabilize compounds and predict their reactivity.

The octet rule states that atoms tend to form stable compounds by gaining, losing, or sharing electrons to attain a noble gas electron configuration with 8 valence electrons (except for hydrogen and helium). It helps predict stable Lewis structures.

The main types are substitution, addition, elimination, rearrangement, oxidation, and reduction reactions.

A nucleophile is an electron-rich species that donates an electron pair, while an electrophile is an electron-deficient species that accepts an electron pair during a reaction.

A free radical is a species with an unpaired electron. They are highly reactive and can initiate chain reactions, often seen in combustion and polymerization processes.

Stereochemistry is the study of the spatial arrangement of atoms in a molecule. It is important because different stereoisomers can have different physical, chemical, and biological properties.

A chiral molecule lacks a plane of symmetry. Enantiomers are mirror-image stereoisomers that are non-superimposable on each other.

The main mechanisms are the SN1 (unimolecular, two steps) and SN2 (bimolecular, one step) mechanisms.

The main mechanisms are the E1 (unimolecular, two steps) and E2 (bimolecular, one step) mechanisms.

A Friedel-Crafts reaction is an electrophilic aromatic substitution reaction, where an alkyl or acyl group is added to an aromatic ring using a Lewis acid catalyst.

The main steps are (1) formation of a pi complex, (2) delivery of hydride, (3) protonation, and (4) elimination of a leaving group.

An SN1 (substitution nucleophilic unimolecular) reaction involves two steps: (1) formation of a carbocation intermediate, and (2) attack of the nucleophile on the carbocation.

An SN2 (substitution nucleophilic bimolecular) reaction is a concerted, one-step process where a nucleophile attacks an alkyl halide or related electrophile, displacing a leaving group.

An E1 (elimination unimolecular) reaction involves two steps: (1) formation of a carbocation intermediate, and (2) removal of a proton by a base to form the alkene product.

An E2 (elimination bimolecular) reaction is a concerted, one-step process where a base extracts a proton from a substrate, and a leaving group departs to form an alkene product.

A pericyclic reaction is a concerted, cyclic reaction where molecular orbitals are conserved, and bonds are formed and broken in a cyclic transition state.

A Diels-Alder reaction is a pericyclic [4+2] cycloaddition reaction between a conjugated diene and a substituted alkene (dienophile) to form a cyclohexene ring.

A retro-Diels-Alder reaction is the reverse of a Diels-Alder reaction, where a cyclohexene derivative undergoes a pericyclic cleavage to form a diene and a dienophile.

Carbocations are positively charged carbon species, while carbanions are negatively charged carbon species. They are key intermediates in many organic reactions.

A protecting group is a chemical moiety that is temporarily introduced into a molecule to mask the reactivity of a specific functional group, allowing selective reactions to occur.

The Curtin-Hammett principle states that the ratio of products formed from competing pathways depends on the relative energies of the transition states, not the initial reactants.

The Woodward-Hoffmann rules are a set of rules that predict the stereochemical outcome and feasibility of pericyclic reactions based on the conservation of orbital symmetry.

The Hammond Postulate states that the transition state of an exothermic reaction resembles the reactants, while the transition state of an endothermic reaction resembles the products.

A protecting group is a chemical moiety that is temporarily introduced into a molecule to mask the reactivity of a specific functional group, allowing selective reactions to occur.

Hyperconjugation is the stabilizing interaction between a filled orbital and an adjacent empty or partially filled orbital, resulting in partial delocalization of electrons.

Enantiotopic atoms or groups are related by a mirror plane and become chemically equivalent upon enantioselective substitution. Diastereotopic atoms or groups are not related by a mirror plane and remain chemically distinct upon substitution.

Regiochemistry deals with the positional selectivity of substituents in a molecule, while stereochemistry deals with the spatial arrangement of atoms or substituents.

The Baeyer strain theory states that cyclohexene derivatives prefer conformations that minimize strain caused by eclipsing interactions between substituents.

In Markovnikov addition, the hydrogen atom goes to the less substituted carbon, while in anti-Markovnikov addition, the hydrogen atom goes to the more substituted carbon.

Kinetic control favors the product with the lowest activation energy barrier, while thermodynamic control favors the most stable product.

A Brønsted acid is a proton donor, while a Lewis acid is an electron pair acceptor. Lewis acids can catalyze reactions even in the absence of protons.

A nucleophile is an electron-rich species that donates an electron pair, while a base is a proton acceptor that removes a proton from an acid.

A protic solvent can donate hydrogen bonds, while an aprotic solvent cannot donate hydrogen bonds but can accept them.

A sigma (σ) bond is formed by head-on overlap of atomic orbitals, while a pi (π) bond is formed by sideways overlap of p-orbitals, resulting in a delocalized electron cloud above and below the bonded atoms.

In a syn addition, the new substituents are on the same side of the double bond, while in an anti addition, the new substituents are on opposite sides of the double bond.

A cycloaddition reaction forms a cyclic product from acyclic reactants, while a cycloelimination reaction forms acyclic products from a cyclic reactant.

In a heterolytic cleavage, a covalent bond breaks such that one atom retains both bonding electrons, forming a cation and an anion. In a homolytic cleavage, each atom retains one electron, forming two radicals.

A carbocation is a positively charged carbon species, while a carbanion is a negatively charged carbon species.

In a conjugated system, p-orbitals overlap, leading to delocalization of pi electrons, while in a non-conjugated system, p-orbitals do not overlap, and electrons are localized.

A radical has an unpaired electron, while a carbene has a divalent carbon with two non-bonding electrons.

A Hofmann elimination involves the removal of a tertiary amine oxide to form an alkene, while a Cope elimination involves the concerted elimination of a sigma bond and formation of a pi bond.

An electrophile is an electron-deficient species that accepts an electron pair, while a nucleophile is an electron-rich species that donates an electron pair.

In an oxidation reaction, electrons are lost by a species, while in a reduction reaction, electrons are gained by a species.

A Grignard reagent is an organomagnesium halide (RMgX), while an organolithium reagent is an organomonolithium compound (RLi). Both are strong nucleophiles and bases.

A sigmatropic reaction involves the migration of a sigma bond, while an electrocyclic reaction involves the formation or cleavage of a pi bond in a cyclic system.

Keto-enol tautomerism involves the migration of a proton between a carbonyl group and an adjacent carbon, resulting in an equilibrium between a keto and an enol form.

An aromatic compound follows the Hückel rule (4n+2 π electrons) and is stabilized by delocalization of pi electrons, while an antiaromatic compound contains a cyclic conjugated system with 4n π electrons, which is destabilized due to disruption of electron delocalization.