Organic Chemistry

Alkanes & Cycloalkanes combustion
Alkane substitution (Cl2, Br2) (CH4 + Cl2 => CH3Cl + HCl)
Free Radical substitution: homolytic fission
Initiation Br2 => Br. + Br.
Termination CH3. , Br. recombine

Unsaturated hydrocarbons
Hydrogenation - catalyst (Pt)
React with Cl2, Br2 - no catalyst
Water {acid catalyst} => alcohol
Isomers => Markovnikov's Rule
HCl / HBr already acidic

Part 2

Alcohol => hydroxyl
OH group polar, hydrogen bonding
Can be formed by the hydration of alkenes
Alkenes may be re-formed by eliminations reactions
Primary secondary tertiary

Aldehyde - terminal (-al)
Ketone - middle (-one)
=> Carbonyl C=O

Ether => ether (-oxy)

Carboxylic acids => carboxyl (-oic acid)

Ester (-oate)

Amine => amino

Amide => amide

Nitrile => nitrile
SP hybridized carbon, Short strong polar triple bond

Slideshow 2
A) Alkanes - see above
B) Oxidation of alcohol (+ O, heat)
Primary and Secondary alcohols can react with KMnO4, [Cr2O7]2-
Reduction of Aldehydes, Ketones
LiAlH4, NaBH4
Only time H- is nucleophile - attracted to positive C of C=O bond
Dry ether

Esterification - condensation
Carboxylic Acid + Alcohol, heated, acid catalyst

Slideshow 3
Nucleophilic substitution
Usually OH-
Sn2 - bimolecular - one step, backside attack - primary leaving group
Better in aprotic solvents (ex propanone / acetone)

Sn1 - unimolecular - 2 steps - tertiary halogenoalkanes
1) {Slow} Leaving group gets electron pair; Carbocation forms (much more stable as tertiary)
2) Nucleophile attacks carbocation, leaving group attracted to H
Steric hindrance
Carbocations stabilized by A) # of carbons attached; B) # of pi bonds; C) # of adjacent lone pairs (N, O, Cl)
Protic solvents preferred (water, alcohols, carboxylic acids)
Leaving group
Rate: Sn1 (carbocation) faster than Sn2 (steric hindrance)

Free Radical Substitution
(see Slideshow 1)

Slideshow 4
Electrophilic Addition
Unsaturated; pi electrons are nucleophile
CH3CH=CH2 + HCl => CH3-(CClH)-CH3
CH2=CH2 + Br2 => Br-CH2-CH2-Br

Hydrogen Halide reaction
May form stereoisomers if carbon is chiral.

Halogen reaction: induced polarization
Dihalogenoalkanes, steric hindrance
Bimolecular 1st step slow
Iodine should be faster than Fluorine

Benzene Electrophilic Substitution

Slideshow 6
Structural, Stereo
Conformation, Configuration
cis-trans / EZ, Optical
1) Higher atomic number is priority
2) Longer carbon chain is priority

Racemic mixture