Organic Chemistry I

1. Organic Chemistry I The study of carbon-containing compounds

2. Unit 1 A little bit of everything…

3. Oops! • We are not starting at the beginning of Chapter 1… • because you need a little more time with the concepts from the following sections: • 2.12, 1.10, 1.11, 2.13, 2.14

4. Hydrocarbons • Compounds that contain only H and C atoms. • alkanes (contain all single bonds) • alkenes (contain C=C) • alkynes (contain C≡C) • aromatics (contain a benzene ring)

5. Alkanes • Each C atom is bonded to 4 other atoms...why? methane CH4 ethane CH3CH3 propane CH3CH2CH3 butane CH3(CH2)2CH3 pentane CH3(CH2)3CH3 hexane CH3(CH2)4CH3 heptane CH3(CH2)5CH3 octane CH3(CH2)6CH3 nonane CH3(CH2)7CH3 decane CH3(CH2)8CH3

6. Alkanes • The most significant reaction of alkanes is combustion. • This is because alkanes do not have any functional groups. • Functional groups are where reactions occur. CH3(CH2)8CH3 + 15.5 O2(g)  10CO2(g) + 11H2O(l)

7. Showing the Structure of an Organic Molecule • You must be able to read and interpret drawings of molecules from the start! • structural formula = Lewis structure • condensed (structural) formula • line-angle formula • 3-dimensional formula • (The molecular formula does not show structure. It just gives numbers and types of atoms.)

8. Molecular Formula, Lewis Structure, and Condensed Structural Formula The Lewis structure shows all bonds and unbonded valence electrons. Please view the Lewis structures PowerPoint on the 2114 web page if you need a refresher. These are all the same compound: cis-hex-3-en-2-one

9. Condensed Structural Formula • The atoms following the C are bonded to the C: CHCl2CH3 • Sometimes the atoms bonded to the leading C are shown on the left: • H3CCH2CH3 or CH3CH2CH3 • The C is bonded to the C immediately before it and the C atom immediately after it…all C atoms in molecules have 4 bonds.

10. Condensed Structural Formula • A group bonded to a C is shown in parentheses, except on the last C. CH3CH2CH2OH is 1-propanol CH3CH(OH)CH3 is 2-propanol • Typically, C=C and C≡C are shown, but C=O is not. CH3CH2CH=CHCOCH3

11. Line-Angle Structure There is a C at the end of every line segment and enough H atoms to give each neutral C four bonds.

12. 3-D Structure • Solid lines are bonds in the plane of the board or paper. • Wedges show bonds to atoms in front of the plane. • Dashed lines show bonds to atoms behind the plane.

13. Showing the Structure of an Organic Molecule • START NOW practicing drawing these different types of structures!

14. Functional Groups • Functional groups are sites of reactivity in an organic compound. Is this compound an alkane? Is it a hydrocarbon? It contains two functional groups: an alkene and a ketone.

15. Functional Groups • In hydrocarbons • alkanes (no functional groups) • alkenes (contain C=C) • alkynes (contain C≡C) • aromatics (contain an aromatic ring, the most common of which is the benzene ring) Two representations of a benzene ring…it is NOT classified as an alkene!

16. Functional Groups • In hydrocarbons

17. Alkyl Substituents • We look for the longest chain of C atoms in the molecule. • Groups of atoms attached to the C atoms in the chain are called substituents.

18. Alkyl Substituents • When the substituent is an alkane, it is called an alkyl group. • The letter R is often used to denote an alkyl substituent. a methyl group any alkyl group

19. Functional Groups • In compounds containing O • alcohols (R-OH) • ethers (R-O-R’) • ketones (contain C=O) • aldehydes (contain HC=O) • carboxylic acids (COOH) • carboxylic acid derivatives • esters (RCOOR’) • amides (RCONH2, RCONHR’, RCONR’R”) • acid chlorides (RCOCl)

20. Functional Groups • In compounds containing N • amines (RNH2, RNHR’, RNR’R”) • amides (RCONH2, RCONHR’, RCONR’R”) • nitriles (R-C≡N) • In compounds containing X • alkyl halides or haloalkanes • X=halogen

21. Functional Groups-Alcohols (R-OH) and Ethers (R-O-R’)

22. Functional Groups-Aldehydes (HC=O) and Ketones (RC=OR’) • C=O is a carbonyl group. • C=O on the end of the carbon chain is an aldehyde. • C=O elswhere in the carbon chain is a ketone.

23. Functional Groups-Carboxylic Acids and Their Derivatives • COOH is a carboxylic acid group. • COOR is an ester. • COCl is an acid chloride.

24. Functional Groups-Amines, Amides, and Nitriles • Amides are like amines, but with an adjacent C=O. • Be careful! Both amines and amides have different forms: primary (1°), secondary (2°), and tertiary (3°). • Nitriles are R-CN.

25. Primary (1°) Amines and Amides • A primary (1°) amine has one C atom (one alkyl group R) and two H atoms bonded to the N. The general formula is RNH2. • A 1° amide has one acyl group and two H atoms bonded to the N. The general formula is RCONH2.

26. Secondary (2°) Amines and Amides • A secondary (2°) amine has two C atoms (two alkyl groups) and one H atom bonded to the N. The general formula is RNHR’. • A 2° amide has two C atoms (one in the acyl group) and one H atom bonded to the N.The general formula is RCONHR’.

27. Tertiary (3°) Amines and Amides • A tertiary (3°) amine has three C atoms (three alkyl groups) and no H atoms bonded to the N. The general formula is RNR’R”. • A 3° amide has three C atoms (one in the acyl group) and no H atoms bonded to the N.The general formula is RCONR’R”.

28. 1°, 2°, 3° Amines and Amides • Classify these.

29. Functional Groups - Alkyl Halides Cycloalkanes are alkanes that have a ring of C atoms. Classify the halides as 1°, 2°, or 3°.

30. Functional Groups Circle and label each functional group. fructose threonine γ-butyrolactone (GBL) acetaminophen vitamin A (retinol)