1. Introduction to Organic Chemistry and Biochemistry Instructor Dr. Upali Siriwardane (Ph.D. Ohio State) E-mail: upali@latech.edu Office: 311 Carson Taylor Hall ; Phone: 318-257-4941; Office Hours: MTW 8:00 - 10:00 am; ThF 9:00 - 10:00 am 1:00 - 2:00 pm. December 19, 2014: Test 1 (Chapters 12-13) January 26, 2015: Test 2 (Chapters 14-16) February 13, 2015: Test 3 (Chapters 17-19) March 2, 2015: Test 4 (Chapters 20-22) March 3, 2015: Make Up Exam: Chapters 12-22) Bring Scantron Sheet 882-E Chemistry 121(001) Winter 2015 1CHEM 121 Winter 15

2. GHW Questions GHW#3 CHEM 121 Winter 152

3. Chapter 12. Saturated Hydrocarbons  12.1 Organic and Inorganic Compounds, 341  12.2 Bonding Characteristics of the Carbon Atom, 342  12.3 Hydrocarbons and Hydrocarbon Derivatives, 342  12.4 Alkanes: Acyclic Saturated Hydrocarbons, 343  12.5 Structural Formulas, 344  12.6 Alkane Isomerism, 346  12.7 Conformations of Alkanes, 348  12.8 IUPAC Nomenclature for Alkanes, 350  12.9 Line-Angle Structural Formulas for Alkanes, 356  12.10 Classification of Carbon Atoms, 358  12.11 Branched-Chain Alkyl Groups, 359  12.12 Cycloalkanes, 361  12.13 IUPAC Nomenclature for Cycloalkanes, 362  12.14 Isomerism in Cycloalkanes, 363  12.15 Sources of Alkanes and Cycloalkanes, 365  12.16 Physical Properties of Alkanes and Cycloalkanes, 367  12.17 Chemical Properties of Alkanes and Cycloalkanes, 368  12.18 Halogenated Alkanes and Cycloalkanes, 371 CHEM 121 Winter 153

4. Chapter 13. Unsaturated Hydrocarbons 13.1 Unsaturated Hydrocarbons, 384 13.2 Characteristics of Alkenes and Cycloalkenes, 385 13.3 IUPAC Nomenclature for Alkenes and Cycloalkenes, 386 13.4 Line-Angle Structural Formulas for Alkenes, 389 13.5 Constitutional Isomerism in Alkenes, 390 13.6 Cis-Trans Isomerism in Alkenes, 391 13.7 Naturally Occurring Alkenes, 394 13.8 Physical Properties of Alkenes and Cycloalkenes, 396 13.9 Chemical Reactions of Alkenes, 396 13.10 Polymerization of Alkenes: Addition Polymers, 402 13.11 Alkynes, 406 13.12 Aromatic Hydrocarbons, 408 13.13 Names for Aromatic Hydrocarbons, 410 13.14 Aromatic Hydrocarbons: Physical Properties and Sources, 413 13.15 Chemical Reactions of Aromatic Hydrocarbons, 413 13.16 Fused-Ring Aromatic Hydrocarbons, 414 CHEM 121 Winter 154

5. etheneethyne benzene C 2 H 4 C 2 H 2 C 6 H 6 C n H 2n C n H 2n  2 C n H n unsaturatedunsaturated Aromatic alkenealkyne Arene Chapters 13 Chapters 13 Chapter 13 Unsaturated Hydrocarbons: Alkenes Alkynes Arenes CHEM 121 Winter 155

6. etheneethyne benzene C 2 H 4 C 2 H 2 C 6 H 6 C n H 2n C n H 2n  2 C n H n Units of Unsaturation C n H 2n+2 C n H 2n  C n H 2n+2 (6-4)/2 =1(6-2)/2 =2(14-6)/2 =4 one double = one triple  three double = 1 ring Units of Unsaturation: Alkenes Alkynes Arenes CHEM 121 Winter 156

7. 1. Write the name of names and units of unsaturation for the hydrocarbons (alkane, alkene, alkyne and arene) with following general formula. C n H 2n+2 C n H 2n C n H 2n-2 C n H n Name a) ______ b) ____ c) ____ d) ___ Unit of unsat. a) ______ b) ____ c) ____ d) ___ CHEM 121 Winter 157

8. Isomerism Isomers Isomers - different compounds having the same molecular formula but different structural formulas There are two type of Isomers: Constitutional isomerism: Different connections among atoms in the Skeleton Position Functional group Stereoisomerism: Same connectivity among atoms, but these atoms differ in spatial orientation geometric conformational optical CHEM 121 Winter 158

9. Constitutional Isomers Positional (Chp. 12) Skeletal (Chp. 12) Enantiomers (Optical) (Chp. 16) Functional (Chp. 14) Stereoisomers Conformational (Chp.12)Geometric (Chp. 13) CHEM 121 Winter 159

10. 2. Draw all constitutional isomers of butane: C 4 H 10. CHEM 121 Winter 1510

11. 3. Names of following cycloalknes : CHEM 121 Winter 1511

12. 4. Complete the following reactions of alkanes. a) Combustion: i) C 5 H 12 (g) + 8 O 2 (g)  ___CO 2 (g) + ___H 2 O(g) ii) C 4 H 10 (g) + ___ O 2 (g)  ___CO 2 (g) + ___H 2 O(g) b) Halogenations: (substitution reaction to form alkyl halides) CHEM 121 Winter 1512

13. Unsaturated hydrocarbons Hydrocarbons with carbon-carbon double bonds and triple bonds double bonds: alkenes triple bonds: alkynes three alternating double bond in 6 carbon ring: aromatics CHEM 121 Winter 1513

14. Unsaturated Hydrocarbons in Use Acetylene: Welding Beta-carotene is in carrots sex pheromones in insect control involves luring insect into a trap. involves luring insect into a trap. Ethene is the hormone that causes tomatoes to ripen. CHEM 121 Winter 1514

15. etheneethyne benzene C 2 H 4 C 2 H 2 C 6 H 6 C n H 2n C n H 2n  2 C n H n unsaturatedunsaturated Aromatic alkenealkyne Arene Chapters 13 Chapters 13 Chapter 13 Unsaturated Hydrocarbons: Unsaturated Hydrocarbons: Alkenes Alkynes Arenes CHEM 121 Winter 1515

16. Nomenclature of Alkenes: Common Names Some alkenes, particularly low-molecular-weight ones, are known almost exclusively by their common names CHEM 121 Winter 1516

17. IUPAC Nomenclature of Alkynes ynuse the infix -yn- to show the presence of a carbon- carbon triple bond number the parent chain to give the 1st carbon of the triple bond the lower number follow IUPAC rules for numbering and naming substituents CHEM 121 Winter 1517

18. Example of IUPAC Nomenclature of Alkenes Cycloalkanes CHEM 121 Winter 1518

19. Naturally Occurring Alkenes Cis-Trans Isomerism – vitamin A has five double bonds – four of the five can show cis-trans isomerism – vitamin A is the all-trans isomer CHEM 121 Winter 1519

20. Naturally Occurring Alkenes: The Terpenes Terpene: a compound whose carbon skeleton can be divided into two or more units identical with the carbon skeleton of isoprene CHEM 121 Winter 1520

21. Terpenes with isoprene units CHEM 121 Winter 1521

22. Terpenes: Polymers of Isopren Terpenes: Polymers of Isoprene myrcenemyrcene, C 10 H 16, a component of bayberry wax and oils of bay and verbena mentholmenthol, from peppermint CHEM 121 Winter 1522

23. Terpenes Vitamin A Vitamin A (retinol) the four isoprene units in vitamin A are shown in red they are linked head to tail, and cross linked at one point (the blue bond) to give the six-membered ring CHEM 121 Winter 1523

24. 5) How many isoprene units a in the following natural product? CHEM 121 Winter 1524

25. 6) Give common name or/and IUPAC names of following compounds a) b) c) d) CHEM 121 Winter 1525

26. Cis and trans Geometrical isomers of alkenes cis two groups are said to be located cis to each other if they lie on the same side of a plane with respect to the double bond. trans If they are on opposite sides, their relative position is described as trans. CHEM 121 Winter 1526

27. Cis-Trans Isomerism Dienes, trienes, and polyenes n 2 n for an alkene with n carbon-carbon double bonds, each of which can show cis-trans isomerism, 2 n cis-trans isomers are possible consider 2,4-heptadiene; it has four cis-trans isomers, two of which are drawn here CHEM 121 Winter 1527

28. 6) Give common name or/and IUPAC names of following compounds e) f) g) h) i) CHEM 121 Winter 1528

29. Physical Properties Alkenes and alkynes are nonpolar compounds the only attractive forces between their molecules are dispersion forces Their physical properties are similar to those of alkanes of similar carbon skeletons those that are liquid at room temperature are less dense than water (1.0 g/m L) they dissolve in each other and in nonpolar organic solvents they are insoluble in water CHEM 121 Winter 1529

30. Summary of Physical State of Unsaturated Hydrocarbons CHEM 121 Winter 1530

31. Reactions of Unsaturated Hydrocarbons CHEM 121 Winter 1531

32. Chemical Reactions of Alkenes 1) Combustion: Alkenes are very flammable and the combustion products are carbon dioxide and water. 2) Addition Reactions: Atoms or group of atoms are added to each a carbon atom of a multiple bond. Two different reactants are involved. a) Symmetric Addition Reactions : Hydrogenation reaction: hydrogenation a hydrogen atom is added to each carbon atom of a double bond. Catalyst (usually Ni or Pt) is needed. Halogenation reaction : In alkene halogenation a halogen atom is added to each carbon atom of a double bond. No catalyst is needed. b) Asymmetric Addition Reactions: both reactants (H-X (X= Cl, OH)) and the alkene need to be asymmetric c) Polymerization of Alkenes: Addition Polymers Polymers are macromolecules in which small units (monomers) are repeated again and again. CHEM 121 Winter 1532

33. Markovnikov’s Rule When an unsymmetrical molecule HQ (e.g., H-Cl, H-OH, H-F) reacts with an unsymmetrical alkene, the hydrogen atom from the HQ becomes attached to the unsaturated carbon atom that already has the most hydrogen atoms CHEM 121 Winter 1533

34. CHEM 121 Winter 1534

35. Hydration Addition of water to the double bond. Textbook page86. CHEM 121 Winter 1535

36. CHEM 121 Winter 1536

37. 7) Complete the reactions of following alkenes CHEM 121 Winter 1537

38. 7) Complete the reactions of following alkenes CHEM 121 Winter 1538

39. CHEM 121 Winter 1539

40. CHEM 121 Winter 1540

41. Aromatic hydrocarbons Aromatic hydrocarbons - organic compounds that had aromas and had different chemical properties from alkane Benzene is the parent compound for the aromatic hydrocarbons. Textbook, page90. Consider benzene. C 6 H 6 CHEM 121 Winter 1541

42. 13 | 42 Space-filling and ball- and-stick models for the structure of benzene. Unsaturated Hydrocarbons cont’d CHEM 121 Winter 15

43. Resonance Structures of Benzene Resonance structures or contributing structures = when two or more structure can be drawn for a compound. In this case, the real structure is something between the proposed structures. CHEM 121 Winter 1543

44. Naming Aromatic Hydroarbons. Monosubstituted benzenes: Ar-CH 2 CH 3 ethylbenzene Ar-CH 2 -CH 2 -CH 2 -CH 3 butylbenzene Ar-CH 3 (methylbenzene) toluene Ar-X (halobenzene) bromobenzene, Ar-NO 2 nitrobenzene Ar-SO 3 H benzenesulfonic acid Ar-NH 2 a nitrile substituent X CHEM 121 Winter 1544

45. CHEM 121 Winter 1545

46. Nomenclature Disubstituted benzenes locate substituents by numbering or use the locators ortho (1,2-), meta (1,3-), and para (1,4-) Where one group imparts a special name, name the compound as a derivative of that molecule CHEM 121 Winter 1546

47. Nomenclature Polysubstituted benzenes – with three or more substituents, number the atoms of the ring – if one group imparts a special name, it becomes the parent name – if no group imparts a special name, number to give the smallest set of numbers, and then list alphabetically CHEM 121 Winter 1547

48. Disubstituted benzenes: 2,6-dibromotoluene p-diethylbenzene 3,5-dinitrotoluene p-cholonitrobenzene o-nitrobenzenesulfonic acid 4-benzyl-1-octene m-cyanotoluene CHEM 121 Winter 1548

49. 8) Match the following names of aromatic hydrocarbons (arenes) to following structures: Anisole, Aniline, Phenol, Benzoic acid, Toluene, Nitrobenzene. Complete the reactions of following alkenes _________ _________ _________ CHEM 121 Winter 1549

50. 9. Give the names of the following disubstituted aromatic hydrocarbons. _________ _________ _________ _________ CHEM 121 Winter 1550

51. 10) Complete the following chemical reactions of aromatic hydrocarbons. CHEM 121 Winter 1551