Schedule Today (4/15): Chapter 21 Wednesday (4/17): Chapter 21 Should have read through at least Section 21.2 Wednesday (4/17): Chapter 21 Read through at least 21.4 Friday (4/19): Chapter 21 Read though at least 21.5 No office hours today.

Organic Chemistry Naming compounds Functional Groups Reactions Systematic IUPAC (International Union of Pure and Applied Chemistry) Functional Groups Alcohols, aldehydes, etc. Reactions

Alkanes These are called “saturated hydrocarbons” (maximum number of hydrogens – no double or triple bonds). Carbon has 4 bonds, hydrogen has 1 bond. CnH2n+2 “Normal” (sometimes n-); others are branched. Structural isomers.

Structural Isomers of Butane CH3CH2CH2CH3 n-butane or butane (CH3)3CH isobutane IUPAC: 2-methylpropane Methylpropane

Alkyl substituents Methanol: CH3OH Ethanol: CH3CH2OH Isopropanol or 2-propanol

Naming Rules (see page 846) For branched hydrocarbons, find the longest chain. Use the lowest number for substituent groups. 3-methylhexane (not 4-methylhexane or 3-ethylpentane) Put substituents in alphabetical order. 4-ethyl-3,5-dimethylnonane (ethyl before methyl)

Structural Isomers of Pentane n-pentane (pentane)

Structural Isomers of Pentane 2-methylbutane (methylbutane)

Structural Isomers of Pentane 2,2-dimethylpropane dimethylpropane

Clicker Question Name this compound. a) 2,2,4,4-tetramethylbutane b) 1,1,3,3-tetramethylbutane c) 1,1,3-trimethylisopentane d) 2,4,4-trimethylpentane e) 2,2,4-trimethylpentane

Clicker Question You visit another university and the professor names a molecule 3-methyl-4-isopropylpentane. Being a UIUC student, you point out that although the correct structure could be drawn, the name did not follow systematic rules. What is the correct systematic name for the molecule? a) 3,4,5-trimethylhexane b) 2-isopropyl-3-methylpentane c) 1,1,2,3-tetramethylpentane d) 2,3,4-trimethylhexane e) 3,4-dimethylheptane

Cyclic Alkanes What is the name of the following compound? 1-isopropyl-3-methylcyclohexane

Alkenes and Alkynes These are called “unsaturated hydrocarbons” Double bonds = alkene Triple bonds = alkyne Alkenes: CnH2n Akynes: CnH2n–2 Cis-trans isomerism

Aromatic Hydrocarbons Note: “phenyl” prefix versus “benzene” suffix. “Phenyl” is used when benzene is a substituent.