1. Naming
1.1. IUPAC
● Parent chain: longest C chain w/ highest-order functional group, should have lowest
possible #
● n-…: normal, straight-chain alkane
● iso-…: terminal iPr group (⦚–CHMe2), or common structural isomer
● sec-…: functional group on 2° C in a 4-carbon chain (e.g., sec-butyl, ⦚–CHMe–CH2–CH3)
● tert-…: functional group on 3° C (e.g., tert-butyl, ⦚–CMe3)
● neo-…: terminal tBu group
1.2. Hydrocarbons, Alcohols
● Alkanes: CnH2n+2 (e.g., H3C–CH3)
○ Meth-…, eth-…, prop-…, but-…, pent-…, hex-…, hept-…, oct-…, non-…, dec-…
● Alkenes: C=C double bond (e.g., H2C=CH2)
● Alkynes: C≡C triple bond (e.g., HC≡CH)
● Aromaticity
○ Hückel’s rules: 4n + 2 π e–, planar, cyclic, conjugated
● Alcohols: hydroxyl (⦚–OH) group
○ Diols: 2 hydroxyls
■ Glycols: aliphatic diols
■ Geminal diols/hydrates: hydroxyls on the same C, spontaneously
dehydrate into carbonyls
■ Vicinal diols: hydroxyls on adjacent C’s
1.3. Aldehydes, Ketones
● Aldehydes (…-al, oxo-…): terminal carbonyl (⦚–C=O) group
○ Formaldehyde: CH2O (methanal)
○ Acetaldehyde: MeCHO (ethanal)
○ Propionaldehyde: EtCHO (propanal)
● Ketones (…-one, oxo/keto-…): non-terminal carbonyl group
○ Acetone: Me2CO (propanone)
○ α-…: C adjacent to carbonyl
■ β-…, γ-…, δ-…, etc.
○ Enone: α,β-unsaturated carbonyl
■ Conjugated system
● Ethers (alkoxy-…, …-yl …-yl ether): R–O–R′
○ Furan, tetrahydrofuran (THF), dioxane, etc.
1.4. Carboxylic Acids
● Carboxylic acids (…-oic acid, …-oate): terminal ⦚–COOH group
○ Formic acid: HCOOH (methanoic acid)
○ Acetic acid: MeCOOH (ethanoic acid)
○ Propionic acid: EtCOOH (propanoic acid)
○ Dicarboxylic acids (…-dioic acid, …-dioate): 2 terminal ⦚–COOH groups
■ Oxalic acid: HOOC–COOH (ethanedioic acid)
■ Malonic acid: HOOC–CH2–COOH (propanedioic acid)
■ Succinic acid: HOOC–CH2–CH2–COOH (butanedioic acid)
● CA derivatives
○ Esters (…-oate): replace hydroxyl w/ alkoxy (⦚–OR) group
■ Esterifying group: R bonded to O
, ■ Lactones (…-lactone): cyclic esters
● α-acetolactone (3-membered), β-propiolactone (4-membered), etc.
○ Amides (…-amide, N-…, N,N-…): R–CONR2, replace hydroxyl w/ amino (⦚–NR2)
group
■ Lactams (…-lactam): cyclic amides
● β-lactam (4-membered), γ-lactam (5-membered), etc.
○ Anhydrides (…-oic anhydride): dehydration between 2 CA groups
1.5. Functional Groups
● Priority: most → least oxidized
○ Alkenes = alkynes
○ Alkenes > alkynes in cyclic compounds
● CAs: …-oic acid, carboxy-…
● Anhydrides: anhydride, alkanoyloxycarbonyl-…
● Esters: …-oate, alkoxycarbonyl-…
● Amides: …-amide, carbamoyl/amido-…
● Aldehydes: …-al, oxo-…
● Ketones: …-one, oxo/keto-…
● Alcohols: …-ol, hydroxy-…
● Alkenes: …-ene, alkenyl-…
● Alkynes: …-yne, alkynyl-…
● Alkanes: …-ane, alkyl-…
2. Isomers
2.1. Structural Isomers
● Structural/constitutional isomers: same molecular formula
○ Usually diff. physical/chemical properties
■ Physical properties: no change in composition
● Density, solubility, melting/boiling point, color, etc.
■ Chemical properties: reactivity, changes composition
● Functional groups
2.2. Stereoisomers
● Stereoisomers: same molecular formula, connectivity
● Conformational isomers/conformers: interconvert by rotating around σ bonds
○ Newman projection: see molecule along C–C bond axis
■ Staggered: no overlaps, antiperiplanar
● Anti: 2 largest groups are on opposite sides, lowest energy, most
stable
● Gauche: 2 largest groups are adjacent
■ Eclipsed: overlapping, synperiplanar
● Totally eclipsed: 2 largest groups overlap, highest energy, least
stable
○ Cyclic conformations
■ Ring strain
● Angle strain: nonideal bond angles
● Torsional strain: eclipsed/gauche interactions
, ● Steric/nonbonded strain/van der Waals repulsion: nonadjacent
groups occupy same space
○ 1,3-diaxial/flagpole interactions: axial–axial steric effects
■ Cyclohexanes
● Chair: axial–equatorial orientations alternate, most stable
○ Bulkiest group favors equatorial to minimize 1,3-diaxial
interactions
● Chair flip: chair ⇌ half-chair ⇌ twist-boat ⇌ boat ⇌ …
● Configurational/optical isomers: interconvert only by reforming bonds
○ Chirality: handedness
■ Chiral center: C w/ 4 diff. groups
○ Enantiomers: opposite configuration at every chiral center
■ Same physical/chemical properties, diff. optical activities/chiral reactions
■ Optical activity: rotation of plane-polarized light by chiral molecule
● Rotates to the right/CW: dextrorotatory (d-…), (+)
● Rotates to the left/CCW: levorotatory (l-…), (–)
● Specific rotation: [α] = αobs / cL, where c = concentration (g/mL), L =
path length (dm)
■ Racemic mixture: equal [enantiomers], no optical activity
● Separate by adding chiral resolving agent: reacts to convert
enantiomers into diastereomers
○ Diastereomers: ≥ 2 stereogenic centers
■ Diff. physical, often diff. chemical properties
■ Cis–trans/geometric isomers: around immovable bonds or rings
■ Meso compounds: have chiral centers, but also internal plane of
symmetry (achiral, no optical activity)
2.3. Relative, Absolute Configurations
● Relative configuration: w.r.t. another chiral molecule (enantiomers, diastereomers,
cis/trans, etc.)
● Absolute conformation: exact spatial arrangement ((E)/(Z), (R)/(S), etc.)
● Cahn–Ingold–Prelog (CIP) priority rules: higher atomic # = higher priority
● Double-bond configuration: assign priorities
○ (Z): 2 highest-priority groups are on same side of double bond
○ (E): on opposite sides
● Chiral centers: assign priorities, rotate molecule so lowest-priority group is in back
○ (R): right/CW
○ (S): left/CCW
○ Fischer projection: horizontal (out from page), vertical (into page)
■ If lowest-priority group is horizontal, then chirality is opposite what we get
■ Switching 2 groups on a chiral center flips chirality
■ Rotating chiral center 90° flips chirality
3. Bonding
3.1. Atomic Orbitals, Quantum Numbers
● Principal (n): size, n ≥ 1
○ Shells/energy levels
○ Each shell holds 2n2 e–
1.1. IUPAC
● Parent chain: longest C chain w/ highest-order functional group, should have lowest
possible #
● n-…: normal, straight-chain alkane
● iso-…: terminal iPr group (⦚–CHMe2), or common structural isomer
● sec-…: functional group on 2° C in a 4-carbon chain (e.g., sec-butyl, ⦚–CHMe–CH2–CH3)
● tert-…: functional group on 3° C (e.g., tert-butyl, ⦚–CMe3)
● neo-…: terminal tBu group
1.2. Hydrocarbons, Alcohols
● Alkanes: CnH2n+2 (e.g., H3C–CH3)
○ Meth-…, eth-…, prop-…, but-…, pent-…, hex-…, hept-…, oct-…, non-…, dec-…
● Alkenes: C=C double bond (e.g., H2C=CH2)
● Alkynes: C≡C triple bond (e.g., HC≡CH)
● Aromaticity
○ Hückel’s rules: 4n + 2 π e–, planar, cyclic, conjugated
● Alcohols: hydroxyl (⦚–OH) group
○ Diols: 2 hydroxyls
■ Glycols: aliphatic diols
■ Geminal diols/hydrates: hydroxyls on the same C, spontaneously
dehydrate into carbonyls
■ Vicinal diols: hydroxyls on adjacent C’s
1.3. Aldehydes, Ketones
● Aldehydes (…-al, oxo-…): terminal carbonyl (⦚–C=O) group
○ Formaldehyde: CH2O (methanal)
○ Acetaldehyde: MeCHO (ethanal)
○ Propionaldehyde: EtCHO (propanal)
● Ketones (…-one, oxo/keto-…): non-terminal carbonyl group
○ Acetone: Me2CO (propanone)
○ α-…: C adjacent to carbonyl
■ β-…, γ-…, δ-…, etc.
○ Enone: α,β-unsaturated carbonyl
■ Conjugated system
● Ethers (alkoxy-…, …-yl …-yl ether): R–O–R′
○ Furan, tetrahydrofuran (THF), dioxane, etc.
1.4. Carboxylic Acids
● Carboxylic acids (…-oic acid, …-oate): terminal ⦚–COOH group
○ Formic acid: HCOOH (methanoic acid)
○ Acetic acid: MeCOOH (ethanoic acid)
○ Propionic acid: EtCOOH (propanoic acid)
○ Dicarboxylic acids (…-dioic acid, …-dioate): 2 terminal ⦚–COOH groups
■ Oxalic acid: HOOC–COOH (ethanedioic acid)
■ Malonic acid: HOOC–CH2–COOH (propanedioic acid)
■ Succinic acid: HOOC–CH2–CH2–COOH (butanedioic acid)
● CA derivatives
○ Esters (…-oate): replace hydroxyl w/ alkoxy (⦚–OR) group
■ Esterifying group: R bonded to O
, ■ Lactones (…-lactone): cyclic esters
● α-acetolactone (3-membered), β-propiolactone (4-membered), etc.
○ Amides (…-amide, N-…, N,N-…): R–CONR2, replace hydroxyl w/ amino (⦚–NR2)
group
■ Lactams (…-lactam): cyclic amides
● β-lactam (4-membered), γ-lactam (5-membered), etc.
○ Anhydrides (…-oic anhydride): dehydration between 2 CA groups
1.5. Functional Groups
● Priority: most → least oxidized
○ Alkenes = alkynes
○ Alkenes > alkynes in cyclic compounds
● CAs: …-oic acid, carboxy-…
● Anhydrides: anhydride, alkanoyloxycarbonyl-…
● Esters: …-oate, alkoxycarbonyl-…
● Amides: …-amide, carbamoyl/amido-…
● Aldehydes: …-al, oxo-…
● Ketones: …-one, oxo/keto-…
● Alcohols: …-ol, hydroxy-…
● Alkenes: …-ene, alkenyl-…
● Alkynes: …-yne, alkynyl-…
● Alkanes: …-ane, alkyl-…
2. Isomers
2.1. Structural Isomers
● Structural/constitutional isomers: same molecular formula
○ Usually diff. physical/chemical properties
■ Physical properties: no change in composition
● Density, solubility, melting/boiling point, color, etc.
■ Chemical properties: reactivity, changes composition
● Functional groups
2.2. Stereoisomers
● Stereoisomers: same molecular formula, connectivity
● Conformational isomers/conformers: interconvert by rotating around σ bonds
○ Newman projection: see molecule along C–C bond axis
■ Staggered: no overlaps, antiperiplanar
● Anti: 2 largest groups are on opposite sides, lowest energy, most
stable
● Gauche: 2 largest groups are adjacent
■ Eclipsed: overlapping, synperiplanar
● Totally eclipsed: 2 largest groups overlap, highest energy, least
stable
○ Cyclic conformations
■ Ring strain
● Angle strain: nonideal bond angles
● Torsional strain: eclipsed/gauche interactions
, ● Steric/nonbonded strain/van der Waals repulsion: nonadjacent
groups occupy same space
○ 1,3-diaxial/flagpole interactions: axial–axial steric effects
■ Cyclohexanes
● Chair: axial–equatorial orientations alternate, most stable
○ Bulkiest group favors equatorial to minimize 1,3-diaxial
interactions
● Chair flip: chair ⇌ half-chair ⇌ twist-boat ⇌ boat ⇌ …
● Configurational/optical isomers: interconvert only by reforming bonds
○ Chirality: handedness
■ Chiral center: C w/ 4 diff. groups
○ Enantiomers: opposite configuration at every chiral center
■ Same physical/chemical properties, diff. optical activities/chiral reactions
■ Optical activity: rotation of plane-polarized light by chiral molecule
● Rotates to the right/CW: dextrorotatory (d-…), (+)
● Rotates to the left/CCW: levorotatory (l-…), (–)
● Specific rotation: [α] = αobs / cL, where c = concentration (g/mL), L =
path length (dm)
■ Racemic mixture: equal [enantiomers], no optical activity
● Separate by adding chiral resolving agent: reacts to convert
enantiomers into diastereomers
○ Diastereomers: ≥ 2 stereogenic centers
■ Diff. physical, often diff. chemical properties
■ Cis–trans/geometric isomers: around immovable bonds or rings
■ Meso compounds: have chiral centers, but also internal plane of
symmetry (achiral, no optical activity)
2.3. Relative, Absolute Configurations
● Relative configuration: w.r.t. another chiral molecule (enantiomers, diastereomers,
cis/trans, etc.)
● Absolute conformation: exact spatial arrangement ((E)/(Z), (R)/(S), etc.)
● Cahn–Ingold–Prelog (CIP) priority rules: higher atomic # = higher priority
● Double-bond configuration: assign priorities
○ (Z): 2 highest-priority groups are on same side of double bond
○ (E): on opposite sides
● Chiral centers: assign priorities, rotate molecule so lowest-priority group is in back
○ (R): right/CW
○ (S): left/CCW
○ Fischer projection: horizontal (out from page), vertical (into page)
■ If lowest-priority group is horizontal, then chirality is opposite what we get
■ Switching 2 groups on a chiral center flips chirality
■ Rotating chiral center 90° flips chirality
3. Bonding
3.1. Atomic Orbitals, Quantum Numbers
● Principal (n): size, n ≥ 1
○ Shells/energy levels
○ Each shell holds 2n2 e–
