# Fundamental Organic Chemistry
## Material Covered in CHEM241 Organic Chemistry I

Instructor: Jean-Claude Bradley at Drexel University
Type of content: vodcast, podcast, PDF, transcript

### Electronic Configuration

Pauli Exclusion Principle: -Only 2 electrons per orbital (opposite spin) -Electrons like to be unpaired if possible
Types of bonds: covalent and ionic
Valence Periodic Table
Solving Lewis Structures
Resonance Hybrids and curved arrow formalism
Lewis, skeletal and condensed structural formulae
Molecular and empirical formulae
Acids and Bases Lowry-Bronsted Acid: PROTONS (H+) Lewis Base: Lone pair of electrons
Molecular Orbitals and Functional Groups
Atomic and Molecular Orbitals: the geometry of electron probability distribution s, p,
Hybrid orbitals sp, sp2, sp3
2 groups of electrons
linear sp
3 groups of electrons
trigonal planar (120o) sp2
4 groups of electrons
tetrahedral (109o)
sp3
Pi and Sigma bonds-the ethylene example
Rigidity of Double Bonds
Isomerism- structural isomers and stereoisomers (geometrical isomers)
Bond polarity and dipole moment Molecule Polarity: sum of dipole moments
Intermolecular Forces Dipole-Dipole interaction (e.g. CH3COCH3 acetone) Hydrogen bonding (e.g. HF, H2O) NEED F,O or N and H van der Waals forces (e.g. He, CH4)
Structure and physical properties Melting point (higher for stronger intermolecular forces) Boiling point (higher for stronger intermolecular forces) Solubility (like dissolves like)
Alkanes, Alkenes, Alkynes, Alcohols, Ethers, Aldehydes and Ketones, Carboxylic Acids Acid Chlorides, Esters, Amides, Amines

### Hydrocarbons

Alkanes have a general formula of C$_n$H$_{n+2}$ (where n is a variable whole number). Alkanes have single carbon to carbon bonds and thus are saturated hydrocarbons and are the least reactive of all hydrocarbons. The boiling tempreture of alkanes increases as the number of carbon atoms increase. The first ten names of the first 10 alkanes are: Let’s count to 10: methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane
Nomenclature: isopropyl, isobutyl, n-butyl, sec-butyl, t-butyl,
Primary, Secondary, Tertiary, Quaternary centers
Reactions of Alkanes 1) combustion 2) cracking 3) halogenation
Conformations of ethane, propane, butane Newman projections Steric Hindrance
Cycloalkanes Cis-trans isomerism of cycloalkanes Chair and boat configurations of cyclohexane Axial and Equatorial positions

### Halogenation of alkanes

Bromination of methane Bond Dissociation Energy Homolysis and Heterolysis Transistion State (Predicting the geometry using the Hammond Postulate) Rate-limiting step
Bromination of propane Chlorination of propane (loss of selectivity) Free-radical stabilities
Carbocations/Carbanions

### Chirality

R and S configurations Optical activity: dextrorotatory and levorotatory Specific rotation Racemic mixture Fisher Projection Diastereomers and Enantiomers Reactions involving chiral centers

### Alkyl halides

Nomenclature
Preparation
1) Free-radical halogenation 2) Hydrohalogenation of alkenes 3) From alcohols 4) From other alkyl halides
Reactions 1) elimination 2) nuleophilic substitution
SN1 and SN2 reactions Solvent effects on nucleophilicity Walden inversion Rearrangements in SN1 reactions (hydride and methyl shifts of carbocations) E-1 and E-2 Reactions Satyzeff Rule

### Alkenes

Alkenes have the general formula C$_n$H$_{2n}$ (where n is a variable whole number). Alkenes contain a double carbon to carbon bond, thus making them more reactive and unsaturated. Alkenes undergo addition reactions in the presence of eg Bromine, where the double carbon to carbon bond is broken the molecule becomes an alkane. Alkenes are non-polar molecules, insoluble in water and the first four alkenes are gases, the others liquids at room tempreture.
Unsaturation Nomenclature Z and E, cis and trans 8 Carbon Rule Preparation 1) Dehydrohalogenation 2) Dehalogenation 3) Dehydration of alcohols 4) Catalytic cracking of alkanes 5) Wittig synthesis
Reactions
1) elimination
2) nuleophilic substitutionSN1 and SN2 reactions
Solvent effects on nucleophilicity
Walden inversion
Rearrangements in SN1 reactions (hydride and methyl shifts of carbocations)
E-1 and E-2 Reactions
Saytzeff's Rule
Alkenes
Unsaturation
Nomenclature
Z and E, cis and trans
8 Carbon Rule
Preparation
1) Dehydrohalogenation
2) Dehalogenation
3) Dehydration of alcohols
4) Catalytic cracking of alkanes
5) Wittig synthesis
Reactions:
Electrophilic addition Markovnikov’s rule Anti-Markovnikov addition Hydration of Alkenes Anti-Markovnikov hydration by hydroboration Catalytic hydrogenation Simmons-Smith reaction Halogenation Hydrohalogenation Epoxidation Permanganate hydroxylation (cold, dilute) Permanganate (warm, concentrated) Ozonolysis OsO4 Carbenes

### Alkynes

Nomenclature
Acidity of alkynes
Preparation
From dihalides From acetylides
Reactions
Hydrogenation Partial hydrogenation (Lindlar’s catalyst) Halogenation Markovnikov addition of HBr Hydration to ketones Permanganate (cold, dilute) Permanganate (warm, concentrated)

### Isomers

molecules such as many larger hydrocarbons can have the same molecular formula but more than one structural formula, these are known as isomers. For example the molecular formula C$_4$H$_{10}$ has two isomers. One structual isomer forms butane while the other molecule can be rearranged to form methylpropane. The larger the molecule the more isomers that can be formed.