Simple Organic Chemistry Basic Structure and Nomenclature

First Ten Alkanes Formula Name CH4 Methane C6H14 Hexane C2H6 Ethane Heptane C3H8 Propane C8H18 Octane C4H10 Butane C9H20 Nonane C5H12 Pentane C10H22 Decane Alkane = CnH2n+2

Straight Chain Alkanes aren’t “Straight” C – C bonds are sp3 hybridized Butane, C4H10

Structural Shorthand Explicit hydrogens (those required to complete carbon’s valence) are usually left off of drawings of hydrocarbons C1 C2 C3 C4 C1 C2 C3 C4 Line intersections represent carbon atoms

Structural Isomers Isomers are molecules with the same chemical formula, but different organization of atoms (different bonding) n-Pentane, C5H12 Isopentane, C5H12 Neopentane, C5H12

Newman Projections Rotation can occur around C – C single bonds Ethane, C2H6

Newman Projections Butane, C4H10

Cyclic Alkanes Cyclopropane, C3H6 Cyclobutane, C4H8 Cyclopentane, C5H10 Cyclohexane, C6H12 Cycloheptane, C7H14 Remember, explicit hydrogens are left out

Rules for Naming Alkanes (Nomenclature) For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon 1 2 3 4 4 carbon chain = butane

Rules for Naming Alkanes (Nomenclature) When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl. —CH3 Methyl —CH2CH3 Ethyl —CH2CH2CH3 Propyl —CH2CH2CH2CH3 Butyl Methyl

Rules for Naming Alkanes (Nomenclature) The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching. 1 2 3 4 Methyl

Rules for Naming Alkanes (Nomenclature) The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents. 1 2 3 4 Name: 2-methylbutane Methyl

Nomenclature Practice Name this compound 1 9 carbons = nonane 2 4 3 5 6 7 8 9 Step #1: For a branched hydrocarbon, the longest continuous chain of carbon atoms gives the root name for the hydrocarbon

Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 Step #2: When alkane groups appear as substituents, they are named by dropping the -ane and adding -yl.

Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 1 9 NOT 9 1 Step #3: The positions of substituent groups are specified by numbering the longest chain of carbon atoms sequentially, starting at the end closest to the branching.

Nomenclature Practice Name this compound 9 carbons = nonane 1 2 4 3 5 6 CH3 = methyl 7 chlorine = chloro 8 9 2-chloro-3,6-dimethylnonane Step #4: The location and name of each substituent are followed by the root alkane name. The substituents are listed in alphabetical order (irrespective of any prefix), and the prefixes di-, tri-, etc. are used to indicate multiple identical substituents.

Alkenes Contain Carbon-Carbon Double bonds Ethene 1  bond

Alkynes Contain Carbon-Carbon Triple Bonds Ethyne 1  bond 1  bond

Reactions of Alkenes and Alkynes Hydrogenation Propene Propane Halogenation 1-Pentene 1-2-dibromopentene Polymerization Small molecules are joined together to form a large molecule Polyethylene

Reactions of Alkenes and Alkynes Hydrogenation Propene Propane Halogenation 1-Pentene 1-2-dibromopentene Polymerization Small molecules are joined together to form a large molecule Polyethylene

Geometric Isomerism in Aromatics ortho (o-) = two adjacent substituents o-dichlorobenzene meta (m-) = one carbon between substituents m-dichlorobenzene para (p-) = two carbons between substituents p-dichlorobenzene

Hydrocarbon Derivatives Class Functional Group General Formula Alcohol hydroxyl group -O — H R – OH Alkyl halide — X R — X Ether — O — R — O — R’ Aldehyde carbonyl group O || — C — H O R — C — H Ketone — C — R — C — R’ Carboxylic acid carboxyl group O — C — OH Ester — C — O— R — C — O — R’ Amine amine group | —N— R’ R — N — R’’