Chapter 1&2, Org. Chem. I, Fall '08 1 Lecture Outline q Organic Chemistry q Relationship of Structure, Energy, and Reactivity q Bonding q Representing molecules (putting the atoms together) o Lewis and Kekulé Structures o Line-angle Formula o 3-D qFunctional Groups q Naming organic compounds Chapter 1&2, Org. Chem. I, Fall '08 2 Organic Chemistry What: The study of carbon-containing compounds Why: Pervasive in nature; Life is based on organic compounds Chemical foundation of biology Improve standard of living (medicines, plastics pesticides . . .) How: Examine structure and analyze how it governs reactivity STRUCTURE Determining the Way in Which Atoms Are Put Together in Space to Form Complex Molecules MECHANISM Understanding the Reactivity of Molecules: How and Why Chemical Reactions Take Place SYNTHESIS Building Complex Molecules From Simple Molecules Using Chemical Reactions Chapter 1&2, Org. Chem. I, Fall '08 3 Chapter 1&2, Org. Chem. I, Fall '08 4 Structure Foundation of organic chemistry 1. What atoms (besides carbon) are important? 2. How are these atoms bonded together? Chapter 1&2, Org. Chem. I, Fall '08 5 Chapter 1&2, Org. Chem. I, Fall '08 6 Summary of Bonding Neutral atoms Charged atoms Chapter 1&2, Org. Chem. I, Fall '08 7 Chapter 1&2, Org. Chem. I, Fall '08 8 Representing Molecules Chapter 1&2, Org. Chem. I, Fall '08 9 Chapter 1&2, Org. Chem. I, Fall '08 10 Chapter 1&2, Org. Chem. I, Fall '08 11 Chapter 1&2, Org. Chem. I, Fall '08 12 Chapter 1&2, Org. Chem. I, Fall '08 13 Examples in order to familiarize with functional groups Chapter 1&2, Org. Chem. I, Fall '08 14 Isomerism Chapter 1&2, Org. Chem. I, Fall '08 15 Chapter 1&2, Org. Chem. I, Fall '08 16 Chapter 1&2, Org. Chem. I, Fall '08 17 Classifying sp3 Atoms by Connectivity I I Chapter 1&2, Org. Chem. I, Fall '08 18 Classifying sp3 Atoms by Connectivity II Chapter 1&2, Org. Chem. I, Fall '08 19 Examples of Classifying Atoms Chapter 1&2, Org. Chem. I, Fall '08 20 Systematic name of most organic compounds Formula Alkene propene Alkyne Alcohol IUPAC name ethyne CH3OH methanol Formula IUPAC name O propanoyl chloride Acyl chloride Acid anhydride Cl O Ethanoic propanoic anhydride O O Ester Ethyl ethanoate O O Ether ethoxyethane Amide O Aldehyde Butanamide O NH2 O ethanal Nitrile cyclohexanone Nitro compound CH3NO2 Nitromethane Butanoic acid Alkyl halide CH3Br bromomethane N Pentanenitrile H Ketone Carboxylic acid O O OH Chapter 1&2, Org. Chem. I, Fall '08 21 Summary of rules for naming alkanes, alkyl halides and ethers 1. Find the longest continuous chain of carbon atoms, and use this chain as the name of the compound. 2. Number the longest chain beginning with the end of the chain nearest a branch. 3. Name the substituent groups attached to the longest chain as alkyl groups. Give the location of each alkyl group by the number of the main-chain carbon atom to which is its attached. 4. When two or more substituents are present, list them in alphabetical order. When two or more of the same alkyl substituent are present, use the prefixes di-, tri-, tetra-, and so on (ignored in alphabetizing), to avoid having to name the alkyl group twice. 5. Alkyl halides and ethers are named as substituted alkanes. X-: “halo-”; RO-: “-oxy” 6. The parent hydrocarbon is numbered in the direction that gives the functional group substituent the lowest possible number. Chapter 1&2, Org. Chem. I, Fall '08 22 Summary of rules for naming a compound with a functional group suffix 1. 2. 3. 4. 5. The parent hydrocarbon is the longest continuous chain containing the functional group. The parent hydrocarbon is numbered in the direction that gives the functional group suffix the lowest possible number. If there is a functional group suffix and a substituent, the functional group suffix gets the lowest possible number. If the same number for the functional group suffix is obtained in both directions, the chain is numbered in the direction that gives a substituent the lowest possible number. If there is more than one subtituent, the substituents are cited in alphabetical order. [Substituent]-[Parent Hydrocarbon]-[Functional Group Suffix] Chapter 1&2, Org. Chem. I, Fall '08 23 Important structures to learn acetone Me Me ether or diethyl ether O acetaldehyde O pyridine N H O formic acid OH phenol Me H acetic acid or AcOH Me toluene O OH O Me OH THF (tetrahydrofuran) DMF (dimethylformamide) O Me Me N H O benzene ethyl acetate or EtOAc DMSO (dimethylsulfoxide) O EtO Me Me O S Me chloroform CHCl3 Methylene chloride CH2Cl2 Chapter 1&2, Org. Chem. I, Fall '08 24