Organic Chemistry

1. Organic Chemistry The Chemistry of Carbon Compounds

2. Carbon

3. “Organic” Chemistry • Historically, organic compounds are defined as compounds extracted or isolated from plants and animals. • VITALISM: Scientists believed that organic compounds contained a vital force that was only found in living systems • Disproved by Friederich Wohler in 1828 by synthesizing urea using inorganic materials (silver cyanate and ammonium chloride)

4. Friederich Wohler

5. Organic Chemistry • Study of carbon compounds • Composed of carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus, and the halogens • More than 95% of known compounds are organic compounds (Carbon-containing) • Recall • Carbons can have 4 bonds • Nitrogen can have 3 bonds • Oxygen can have 2 bonds • Hydrogen can have 1 bond

6. Common Elements in Organic Compounds C, H, O, (N, S)

7. The Secret to Organic Compounds: the unique carbon atom • CATENATION • Ability of C-atoms to bond to each other so strongly, they can form long chains. Eg. Thousands of C-atoms bonded. • Each carbon can have four bonds, maximum

8. Common organic compound families • HYDROCARBONS: Only C and H • Alkanes, alkenes, alkynes, arenes, aromatic compounds • OXYGEN-CONTAINING • Alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, acid anhydrides • NITROGEN-CONTAINING • Amines, Amides

9. Examples

10. Classification of Hydrocarbons

11. Hydrocarbons

12. Hydrocarbons: Alkanes • Simplest hydrocarbons • Contains only C–C and C–H bonds • Usually used as fuels • Three types • Straight chain alkanes • Branched alkanes • Cyclic alkanes

13. Examples of Alkanes

14. Structures of Alkanes

15. Structural Isomers

16. Structural Isomers

17. Cycloalkanes • Alkanes that form rings are called cycloalkanes

18. Haloalkanes • Alkanes with halogens Freon 11 Freon 12 Freon 14

19. Chlorofluorocarbons • Insoluble in water and are unreactive towards substances • Unreactiveness lets them reach the stratosphere and react with the ozone layer

21. Alkenes

22. Alkynes • Contains a C≡C bonds

23. August Kekule and the Dream • C6H6

24. "I fell into a reverie, and lo, the atoms were gamboling before my eyes! Whenever, hitherto, these diminutive beings had appeared to me, they had always been in motion; but up to that time, I had never been able to discern the nature of their motion. Now, however, I saw how, frequently, two smaller atoms united to form a pair; how a larger one embraced the two smaller ones; how still larger ones kept hold of three or even four of the smaller; whilst the whole kept whirling in a giddy dance. I saw how the larger ones formed a chain, dragging the smaller ones after them, but only at the ends of the chain. . . The cry of the conductor: “Clapham Road,” awakened me from my dreaming; but I spent part of the night in putting on paper at least sketches of these dream forms. This was the origin of the Structural Theory." • "...I was sitting writing on my textbook, but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold conformation; long rows sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis."

25. H H C H H C H H C C C C C C C C H H C H H C H H Aromatic Hydrocarbons 24.3

26. Aromatic Hydrocarbons • Cyclic structures with alternating C–C and C=C bonds

27. Polycyclic Aromatic Hydrocarbons 24.3

28. Functional Groups • Determines the properties of the organic compound • Compounds with the same functional group will react similarly • Alkenes: –C=C– bond • Alkynes: –C≡C– bond • Aromatic hydrocarbons: cyclic structure with alternating –C–C– and –C=C– bonds

29. Alcohols • has the general structure R–OH • derived from hydrocarbons and contain -OH groups • Polar molecules and are soluble in water (Why?)

30. Some Common Alcohols • CH3OH (methanol) • Used as an industrial solvent • Possible replacement for gasoline in automobiles • CH3CH2OH (ethanol) • Made from fermentation of grain or other sugar materials • Made by reaction of ethylene with water (denatured alcohol) • Used for beverages and fuels

31. Some Common Alcohols • Isopropyl Alcohol • Also known as rubbing alcohol • Used as a disinfectant • Ethylene glycol • Also known as antifreeze • Has multiple –OH groups

32. Alcohols Sterols, ethylene glycol

33. enzyme C6H12O6(aq) 2CH3CH2OH (aq) + 2CO2 (g) H2SO4 CH2 CH2(g) + H2O (g) CH3CH2OH (g) alcohol dehydrogenase CH3CH2OH CH3CHO + H2 Biological production of ethanol Commercial production of ethanol Metabolic oxidation of ethanol DRINKABLE vs. DENATURED Alcohol

34. Ethers • Has the R-O-R’ general structure • Compounds in which two hydrocarbons linked by an oxygen are called ethers. • Used as general anesthetic • Used as solvents • Less soluble in water than alcohols

35. Ethers

36. Compounds with a Carbonyl Group • Carbonyl functional group is C=O • Types of different carbonyl compounds • Aldehydes • Ketones • Carboxylic Acids • Esters • Amides

37. Aldehydes and Ketones • Aldehydes must have at least one H atom attached to the carbonyl group: • Ketones must have two C atoms attached to the carbonyl group:

38. O O O CH3 CH3 formaldehyde acetaldehyde acetone H C H H C C ALMONDS, FORMALIN H3C Functional Group Chemistry

39. Carboxylic Acids • Carboxylic acids contain a carbonyl group with an -OH attached. • The carboxyl functional group is -COOH • Carboxylic acids are weak acids. VINEGAR, ASPIRIN, FACIAL WASH, ANTS, CITRUS FRUITS, PROTEINS, PRESERVATIVES

40. Common Carboxylic Acids

41. Esters • Esters contain -COOR groups: • Usually have fruity odors and tastes

42. Ester Flavors and Fragrances

43. O CH3COOH + HOCH2CH3 CH3 C O CH2CH3 + H2O Functional Group Chemistry Esters have the general formula R’COOR, where R is a hydrocarbon group. ethyl acetate Banana: isopentyl acetate Pineapple: ethyl butanoate Apple: methyl butanoate Pear: propyl ethanoate Orange: Octyl ethanoate Raspberry: 2-Methylpropyl ethanoate Oil of Wintergreen: methyl salycilate

44. Esters Galore!     allyl caproate     pineapple         amyl acetate         apple, banana         amyl butyrate      apricot, pear, pineapple                 amyl caproate     apple, pineapple         amyl valerate        apple         benzyl  acetate      pear, strawberry         bornyl acetate      pine tree flavor         iso-butyl acetate   cherry, raspberry, strawberry ethyl acetate          peach, pineapple, raspberry ethyl butyrate         banana, pineapple, strawberry         ethyl caproate        strawberry         ethyl cinnamate     cinnamon         ethyl formate         lemon, strawberry         ethyl heptoate        grape, pineapple         ethyl isovalerate     apple         ethyl heptanoate   apricot, cherry, grape, raspberry         ethyl lactate           grape       ethyl pelargonate         grape         geranyl acetate                 geranium         geranyl butyrate                 cherry         geranyl valerate                 apple         linalyl acetate                 lavender,sage         linalyl butyrate                 peach         linalyl formate                 apple, peach menthyl acetate                 peppermint         methyl benzyl acetate         cherry         methyl cinnamate               strawberry         methyl phenyl acetate        honey methyl salicylate               wintergreen         methyl anthranilate             grape,jasmine         nonyl caprylate                 orange         octyl butyrate                   parsnip         terpenyl butyrate               cherry

45. HOW TO MIMIC NATURE: Making synthetic flavoring • A good cherry is supposed to be tough to formulate.  Here is an example of a *minimum* synthetic cherry flavoring: •         ethyl methyl p-tolyl glycidate          16.0 %         iso-amyl acetate                        12.0 %         iso-butyl acetate                       12.0 %         p-methyl benzyl acetate                 11.0 %         benzaldehyde                             8.0 %         vanillin                                 7.0 %         benzyl alkcohol                          5.5 %         piperonal                                5.0 %         ethyl caprate                            4.0 %         cinnamic aldehyde dimethyl acetal        3.0 %         p-tolyl aldehyde                         3.0 %         cinnamyl anthranilate                    3.0 %         ethyl caproate                           2.0 %         geranyl butyrate                         2.0 %         terpenyl butyrate                        0.5 %

46. Amines • Organic bases • Contain carbon, hydrogen, and nitrogen

47. Amides • composites of carbonyl and amine functionalities • proteins

49. Name the functional group

50. Compounds with multiple functional groups