Organic Chemistry by Owen Borville 11.7.2025
Organic chemistry is the study of compounds that contain carbon and hydrogen. Examples are methane (CH4), ethane (C2H6), propane (C3H8), butane (C4H10), hexane (C6H14), acetic acid (C2H4O2), benzene (C6H6), and glucose (C6H12O6).
Carbon tends to complete its octet by sharing electrons: electron configuration effectively prohibits ion formation. Carbon forms four covalent bonds.
Carbon forms strong carbon-carbon bonds due to small size. Hybridization and small size result in relatively strong pi π bonds. Carbon has no d electrons or orbitals that are susceptible to attack.
Carbon forms chains containing single, double, and triple carbon-carbon bonds. Each carbon atom in a compound is classified by the number of other carbon atoms bonded to it: Primary (1°): bonds to one other carbon. Secondary (2°): bonds to two other carbons. Tertiary (3°): bonds to three other carbons. Quaternary (4°): bonds to four other carbons.
Classification of Organic Compounds
Aromatic compounds are organic compounds that are related to benzene or contain benzene rings (C6H6): benzene, phenol (benzene + OH), and cinnamic aldehyde (benzene + CH=CH-C-H=O).
Aliphatic compounds are organic compounds that do not contain the benzene ring: ethanol (CH3CH2OH), butyric acid (CH3CH2CH2C=OOH), acetone (CH3C=OCH3)
A variety of different types of organic compounds result from: (1) ability of carbon to form chains by bonding with itself (2) the presence of elements other than carbon and hydrogen (3) functional groups (4) multiple bonds
Alkanes are organic compounds made up of only carbon and hydrogen atoms, where all of the bonds between carbon atoms are single covalent bonds.
An alkyl group is a portion of a molecule that resembles an alkane. Ex. methyl-, ethyl-, propyl-, isopropyl-, butyl-, pentyl-, isopentyl-, hexyl-, heptyl-, octyl-. An alkyl group is a molecular fragment derived from an alkane by removing one hydrogen atom, and creating a point of attachment for a larger molecules.
A functional group is a group of atoms within a molecule that determines many of a molecule's chemical properties including reactivity. Ex. Hydroxy group, Carboxy group, Ester group, Carbonyl group, Amino group, Amide group.
Many compounds contain more than one functional group. An amino acid (Ex. alanine) contains both an amide group and the carboxyl group.
Organic compounds are named using IUPAC (International Union of Pure and Applied Chemistry) rules: (1) the longest continuous linear carbon chains contain five C atoms. The carbon chain could be lengthened if one or more carbons are connected to the left or right in the atomic structure (forming an L shaped chain). (2) Carbon atoms are numbered beginning at the end of the nearest substituent group. (3) the substituent group is named based on where it attaches to the carbon chain. If the substituent group attaches to the carbon chain nearest to the second carbon, then the name of the compound begins with (2-), then the name of the substituent, then the prefix is named after the number of carbon atoms in the chain. A five-carbon chain would end with the name pentane.
Molecules with Multiple Substituents: When there are two or more different substituents, the substituent names are alphabetized. Prefixes for identical substituents are not used in the alphabetization, only the substituent name.
Classification of molecules with specific functional groups:
Alcohols: (1) Identify the longest C chain that includes the -OH group (2) the ending changes to -ol (3) give the lowest number to the C with the -OH group.
Carboxylic acids: (1) Identify the longest C chain that includes the -COOH group (2) the ending changes to -oic acid (3) number the carbons starting with the carbonyl carbon
Esters: (1) Name as a derivative of a carboxylic acid (2) the ending changes from -ic acid to -ate
Aldehydes: (1) Identify the longest C chain that includes the -COH group (2) the ending changes to -al (3) number the carbons starting with the carbonyl carbon
Ketones: (1) Identify the longest C chain that includes the -CO group (2) the ending changes to -one (3) number the carbons to give the carbonyl carbon the lowest number
Primary Amines: (1) Identify the longest C chain that includes the -NH2 group (2) the ending changes to -amine (3) give the lowest number to the C with the -NH2 group
Primary Amides: (1) Name as a derivative of a carboxylic acid (2) the ending changes from -oic acid to -amide (3) may also replace -e with -amide
Representing organic molecules correctly is important because the atoms may be arranged in many different ways.
A condensed structural formula or condensed structure shows the same information as a structural formula, but in a condensed form.
Molecular formula: C8H18
Structural formula: CH3CH2CH2CH2CH2CH2CH2CH3
Condensed Structural formula: CH3 (CH2)6 (CH3)
Kekulé structures are similar to Lewis Structures, except that they do not show lone pairs.
Skeletal structures consist of straight lines that represent carbon-carbon bonds. Carbon atoms are not shown. Hydrogen atoms attached to carbon atoms are not shown either. Zig zag lines are used for carbon chains, linear lines are used for triple bonds, all other atoms are shown (non C or H). A substituent is shown with an extra line attached to the zig-zag.
Heteroatoms are atoms other than carbon or hydrogen. If hydrogen is attached to a heteroatom, it must be included in the skeletal structure.
Resonance structures: A curved arrow is used to specify the differences in positions of electrons in resonance structures.
Isomers are different compounds that have the same chemical formula (Ex. butane and iso-butane, C4H10; ethanol and dimethyl ether C2H6O) Constitutional isomerism occurs when the same atoms can be connected in two or more different ways.
Stereoisomers are those that contain identical bonds but differ in the orientation of those bonds in space. Two types of stereoisomers: Geometrical isomers occur in compounds that have restricted rotation around a bond. Compounds that form double bonds can form geometrical isomers. Ex. cis-2-butene and trans-2-butene (C4H8). In sis-2-butene, the two methyl groups are on the same side as the double bond, while in trans-2-butene, they are on opposite sides.
Optical Isomers are stereoisomers that are mirror images of each other, but are not superimposable (ex. your left and right hand). Chiral molecules have nonsuperimposable mirror images. Enantiomers are pairs of molecules that are mirror images of each other. Most chemical properties of enantiomers and all of their physical properties are identical.
Three Dimensional Molecules are represented on paper using solid lines, dashes, and wedges. Solid lines represent bonds that lie in the plane of the page. Dashes represent bonds that point behind the page. Wedges represent bonds that point in front of the page.
Enantiomers are optically active. If the plane of polarization is rotated to the right, the isomer is dextrorotary. If the plane of polarization is rotated to the left, the isomer is levorotary. In an equimolar mixture of both enantiomers (racemic mixture), the net rotation is zero.
Electrophiles are species with a positive or partial positive charge. Electrophiles are electron-loving and are attracted to a region of negative charge or partial negative charge. Electrophiles are electron poor.
Nucleophiles are species with a negative or partial negative charge. Nucleophiles "love a nucleus." Nucleophiles are attracted to a region of positive charge or a partial positive charge. Nucleophiles are electron rich.
Addition reactions are those that forms a new bond to a carbon. Electrophilic addition is when an electrophile attacks a region of electron density.
Nucleophilic addition is when a bond forms when a nucleophile donates a pair of electrons to an electron-deficient atom.
Substitution reactions occur when one group is replaced by another group. Electrophilic substitution occurs when an electrophile attacks an aromatic molecule and replaces a hydrogen atom.
Nucleophilic substitution occurs when a nucleophile replaces another group on a carbon atom.
Elimination reactions are those in which a double bond forms and a molecule such as water is removed.
Oxidation-reduction reactions involve the loss and gain of electrons. When a molecule gains O or loses H, it is oxidized.
Isomerization reactions are those in which one isomer is converted into another. Ex. conversion of glucose to fructose.
Polymers are molecular molecules that are made up of many repeating units called monomers. Polymers usually have very high molar masses.
Addition polymers form when monomers such as ethylene join end to end to make polyethylene. Addition polymer formation: (1) Initiation step: a radical-a species that contains an unpaired electron- attacks a carbon atom on an ethylene molecule. (2) the double bond breaks, and a bond forms between the original radical and the ethylene molecule. A new radical forms. (5) the new radical attacks another ethylene molecule forming another radical in a step called propagation. (6) termination occurs until the radicals encounter another radical.
Condensation polymers form when molecules with two different functional groups combine, with the elimination of a small molecule, commonly water.
Copolymers are made up of two or more different molecules, such as when two polymers join together by condensation.
Naturally occurring polymers or biological polymers are proteins, polysaccharides, and nucleic acids. Proteins are polymers of amino acids. The bonds that form between amino acids are peptide bonds. Very long chains of condensed amino acids are proteins.
Polysaccharides are polymers of sugars such as glucose and fructose.
Nucleic acids are polymers of nucleotides. Two important nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Each nucleotide contains a base, a furanose sugar, and a phosphate group.
Organic chemistry is the study of compounds that contain carbon and hydrogen. Examples are methane (CH4), ethane (C2H6), propane (C3H8), butane (C4H10), hexane (C6H14), acetic acid (C2H4O2), benzene (C6H6), and glucose (C6H12O6).
Carbon tends to complete its octet by sharing electrons: electron configuration effectively prohibits ion formation. Carbon forms four covalent bonds.
Carbon forms strong carbon-carbon bonds due to small size. Hybridization and small size result in relatively strong pi π bonds. Carbon has no d electrons or orbitals that are susceptible to attack.
Carbon forms chains containing single, double, and triple carbon-carbon bonds. Each carbon atom in a compound is classified by the number of other carbon atoms bonded to it: Primary (1°): bonds to one other carbon. Secondary (2°): bonds to two other carbons. Tertiary (3°): bonds to three other carbons. Quaternary (4°): bonds to four other carbons.
Classification of Organic Compounds
Aromatic compounds are organic compounds that are related to benzene or contain benzene rings (C6H6): benzene, phenol (benzene + OH), and cinnamic aldehyde (benzene + CH=CH-C-H=O).
Aliphatic compounds are organic compounds that do not contain the benzene ring: ethanol (CH3CH2OH), butyric acid (CH3CH2CH2C=OOH), acetone (CH3C=OCH3)
A variety of different types of organic compounds result from: (1) ability of carbon to form chains by bonding with itself (2) the presence of elements other than carbon and hydrogen (3) functional groups (4) multiple bonds
Alkanes are organic compounds made up of only carbon and hydrogen atoms, where all of the bonds between carbon atoms are single covalent bonds.
An alkyl group is a portion of a molecule that resembles an alkane. Ex. methyl-, ethyl-, propyl-, isopropyl-, butyl-, pentyl-, isopentyl-, hexyl-, heptyl-, octyl-. An alkyl group is a molecular fragment derived from an alkane by removing one hydrogen atom, and creating a point of attachment for a larger molecules.
A functional group is a group of atoms within a molecule that determines many of a molecule's chemical properties including reactivity. Ex. Hydroxy group, Carboxy group, Ester group, Carbonyl group, Amino group, Amide group.
Many compounds contain more than one functional group. An amino acid (Ex. alanine) contains both an amide group and the carboxyl group.
Organic compounds are named using IUPAC (International Union of Pure and Applied Chemistry) rules: (1) the longest continuous linear carbon chains contain five C atoms. The carbon chain could be lengthened if one or more carbons are connected to the left or right in the atomic structure (forming an L shaped chain). (2) Carbon atoms are numbered beginning at the end of the nearest substituent group. (3) the substituent group is named based on where it attaches to the carbon chain. If the substituent group attaches to the carbon chain nearest to the second carbon, then the name of the compound begins with (2-), then the name of the substituent, then the prefix is named after the number of carbon atoms in the chain. A five-carbon chain would end with the name pentane.
Molecules with Multiple Substituents: When there are two or more different substituents, the substituent names are alphabetized. Prefixes for identical substituents are not used in the alphabetization, only the substituent name.
Classification of molecules with specific functional groups:
Alcohols: (1) Identify the longest C chain that includes the -OH group (2) the ending changes to -ol (3) give the lowest number to the C with the -OH group.
Carboxylic acids: (1) Identify the longest C chain that includes the -COOH group (2) the ending changes to -oic acid (3) number the carbons starting with the carbonyl carbon
Esters: (1) Name as a derivative of a carboxylic acid (2) the ending changes from -ic acid to -ate
Aldehydes: (1) Identify the longest C chain that includes the -COH group (2) the ending changes to -al (3) number the carbons starting with the carbonyl carbon
Ketones: (1) Identify the longest C chain that includes the -CO group (2) the ending changes to -one (3) number the carbons to give the carbonyl carbon the lowest number
Primary Amines: (1) Identify the longest C chain that includes the -NH2 group (2) the ending changes to -amine (3) give the lowest number to the C with the -NH2 group
Primary Amides: (1) Name as a derivative of a carboxylic acid (2) the ending changes from -oic acid to -amide (3) may also replace -e with -amide
Representing organic molecules correctly is important because the atoms may be arranged in many different ways.
A condensed structural formula or condensed structure shows the same information as a structural formula, but in a condensed form.
Molecular formula: C8H18
Structural formula: CH3CH2CH2CH2CH2CH2CH2CH3
Condensed Structural formula: CH3 (CH2)6 (CH3)
Kekulé structures are similar to Lewis Structures, except that they do not show lone pairs.
Skeletal structures consist of straight lines that represent carbon-carbon bonds. Carbon atoms are not shown. Hydrogen atoms attached to carbon atoms are not shown either. Zig zag lines are used for carbon chains, linear lines are used for triple bonds, all other atoms are shown (non C or H). A substituent is shown with an extra line attached to the zig-zag.
Heteroatoms are atoms other than carbon or hydrogen. If hydrogen is attached to a heteroatom, it must be included in the skeletal structure.
Resonance structures: A curved arrow is used to specify the differences in positions of electrons in resonance structures.
Isomers are different compounds that have the same chemical formula (Ex. butane and iso-butane, C4H10; ethanol and dimethyl ether C2H6O) Constitutional isomerism occurs when the same atoms can be connected in two or more different ways.
Stereoisomers are those that contain identical bonds but differ in the orientation of those bonds in space. Two types of stereoisomers: Geometrical isomers occur in compounds that have restricted rotation around a bond. Compounds that form double bonds can form geometrical isomers. Ex. cis-2-butene and trans-2-butene (C4H8). In sis-2-butene, the two methyl groups are on the same side as the double bond, while in trans-2-butene, they are on opposite sides.
Optical Isomers are stereoisomers that are mirror images of each other, but are not superimposable (ex. your left and right hand). Chiral molecules have nonsuperimposable mirror images. Enantiomers are pairs of molecules that are mirror images of each other. Most chemical properties of enantiomers and all of their physical properties are identical.
Three Dimensional Molecules are represented on paper using solid lines, dashes, and wedges. Solid lines represent bonds that lie in the plane of the page. Dashes represent bonds that point behind the page. Wedges represent bonds that point in front of the page.
Enantiomers are optically active. If the plane of polarization is rotated to the right, the isomer is dextrorotary. If the plane of polarization is rotated to the left, the isomer is levorotary. In an equimolar mixture of both enantiomers (racemic mixture), the net rotation is zero.
Electrophiles are species with a positive or partial positive charge. Electrophiles are electron-loving and are attracted to a region of negative charge or partial negative charge. Electrophiles are electron poor.
Nucleophiles are species with a negative or partial negative charge. Nucleophiles "love a nucleus." Nucleophiles are attracted to a region of positive charge or a partial positive charge. Nucleophiles are electron rich.
Addition reactions are those that forms a new bond to a carbon. Electrophilic addition is when an electrophile attacks a region of electron density.
Nucleophilic addition is when a bond forms when a nucleophile donates a pair of electrons to an electron-deficient atom.
Substitution reactions occur when one group is replaced by another group. Electrophilic substitution occurs when an electrophile attacks an aromatic molecule and replaces a hydrogen atom.
Nucleophilic substitution occurs when a nucleophile replaces another group on a carbon atom.
Elimination reactions are those in which a double bond forms and a molecule such as water is removed.
Oxidation-reduction reactions involve the loss and gain of electrons. When a molecule gains O or loses H, it is oxidized.
Isomerization reactions are those in which one isomer is converted into another. Ex. conversion of glucose to fructose.
Polymers are molecular molecules that are made up of many repeating units called monomers. Polymers usually have very high molar masses.
Addition polymers form when monomers such as ethylene join end to end to make polyethylene. Addition polymer formation: (1) Initiation step: a radical-a species that contains an unpaired electron- attacks a carbon atom on an ethylene molecule. (2) the double bond breaks, and a bond forms between the original radical and the ethylene molecule. A new radical forms. (5) the new radical attacks another ethylene molecule forming another radical in a step called propagation. (6) termination occurs until the radicals encounter another radical.
Condensation polymers form when molecules with two different functional groups combine, with the elimination of a small molecule, commonly water.
Copolymers are made up of two or more different molecules, such as when two polymers join together by condensation.
Naturally occurring polymers or biological polymers are proteins, polysaccharides, and nucleic acids. Proteins are polymers of amino acids. The bonds that form between amino acids are peptide bonds. Very long chains of condensed amino acids are proteins.
Polysaccharides are polymers of sugars such as glucose and fructose.
Nucleic acids are polymers of nucleotides. Two important nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Each nucleotide contains a base, a furanose sugar, and a phosphate group.
