2. Goals for the Day: Reviewing Exam Naming Alcohols Physical Properties of Alcohols Naming Ethers, Thiols & Phenols Physical Properties of Ethers, thiols & phenols

3. Alcohols, Phenols, and Thiols An alcohol contains a hydroxyl group (–OH) attached to a carbon chain. A phenol contains a hydroxyl group (–OH) attached to a benzene ring. A thiol contains a thiol group (–SH) attached to a carbon chain. 3

4. Naming Alcohols… Recall the IUPAC rules…and add…. 1)The carbon containing the alcohol must be contained in the longest chain of carbons 2)The carbon containing the alcohol gets priority in the numbering 3)The suffix becomes –anol

5. A few small names… Isopropanol or isopropyl alcohol or 2-hydroxy propane propanol ethanol Tertbutyl alcohol

6. Naming Alcohols Let’s practice naming a few together… 6

7. Answers… 7

8. Your Book’s Guide to Naming Alcohols 8

9. Learning Check Name the following using the IUPAC system… Where would we start numbering…a, b, or c? 9

10. Working through the name… Remember rule 1…the carbon with the OH has to be part of the longest chain, so the longest chain is highlighted…the base name is octanol. 10

11. Working through the name… Remember rule 2, give the carbon with the OH the smallest possible number, so this is 2- octanol. 11

12. Working through the name… The last thing is to add the attachment. It is on carbon 3, and has four carbons, so the complete name is: 3-butyl-2- octanol. 12

13. Learning Check Draw ONE of the condensed or line structural formula of the following in your composition book…. A. 3-Pentanol B. Propyl alcohol C. 3-Methylcyclohexanol 13

14. A. 3-Pentanol B Propyl alcohol CH 3 —CH 2 —CH 2 —OH C. 3-Methylcyclohexanol 14

15. Degree of Alcohols…count the number of carbons attached to the carbon with the –OH group. Isopropanol - secondary alcohol (it has 2 carbons –or “R” groups and 1 H). Ethanol - a primary alcohol (it has 1 Carbon or “R” and 2 H’s) Tertbutyl alcohol – a tertiary alcohol (it has 3 carbons – or “R” groups and No hydrogens).

16. Learning Check Classify each of the following alcohols as primary, secondary, or tertiary. A. isopropyl alcohol, 2-propanol B. 1-butanol C. D. 16

17. Solution A. isopropyl alcohol, 2-propanol secondary B. 1-butanolprimary C. tertiary D.secondary 17

18. Draw a tertiary alcohol in your composition books & try to name it! …

19. An example of a tertiary alcohol… Remember, the carbon with the OH will have three other carbon atoms (with the arrows pointing towards them) attached in a tertiary alcohol. This is 2-methyl-2-butanol.

20. Some Typical Alcohols Rubbing alcohol: 2-Propanol (isopropyl alcohol) Antifreeze: 1,2 - Ethanediol (ethylene glycol) Glycerol: 1,2,3 - Propanetriol 20

21. Physical Properties…. Boiling Points & Melting Points Solubility in Water

22. Boiling Points of Alcohols Alcohols Have and OH group, so have the ability to form hydrogen bonds between alcohol molecules. have higher boiling points than alkanes and ethers of similar mass.

23. Comparing to other functional groups… The alkane trend (straight line) is typical of an increase just due to Molecular weight (i.e. increasing m.w. increases mp & bp). The alcohols start out about 100 degrees higher, then as the become More “alkane like” (i.e. have more carbons than oxygens), their trend Will eventually match the one of the alkanes.

24. Practice Ranking… Rank highest to lowest boiling point.. a b c >> highest

25. Practice Ranking… Rank highest to lowest boiling point.. a b c >> c a b

26. Solubility of Alcohols in Water Alcohols are more soluble in water than are alkanes because the oxygen atom can form hydrogen bonds with water. Alcohol Solubility in H 2 O 1–3 carbon atomscompletely soluble 4 carbon atomsslightly soluble 5 or more carbon atomsinsoluble 26

27. Solubility of Alcohols in Water 27

28. Which would be soluble in water? We will go through these together…

29. Which would be soluble in water? Actually, just propanol will be soluble. Too many carbons too many carbons alkane

30. Learning Check Which compound would be more soluble in water, ethanol or 2-pentanol? Explain. 30

31. Solution Which compound would be more soluble in water, ethanol or 2-pentanol? Explain. Ethanol has 2 carbon atoms in its chain. It is more soluble than pentanol with 5 carbons. The longer the alkyl chain, the less soluble the alcohol in water. 31

32. Comparing Trends in Alcohol Solubility and Boiling Points 32

33. Draw an example of an alcohol that would be soluble in water on your composition book…

34. Some possibilities…

35. Moving on to ethers, phenols, and thiols…

36. Ethers, Phenols, and Thiols An ether contains an Oxygen inserted in a carbon chain. A phenol contains a hydroxyl group (–OH) attached to a benzene ring. A thiol contains a thiol group (–SH) attached to a carbon chain. 36 Ether

37. Reminder about naming Phenols… To name a phenol with two substituents, assign C-1 to the carbon attached to the –OH. number the ring to give the substituents the lowest numbers. use prefixes o, m, and p for common names. 37 Phenol 3-chlorophenol (m-chlorophenol)

38. Derivatives of Phenol Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint. 38

39. Solubility of Phenol Is not soluble in water unless it is ionized! has a hydroxyl group that ionizes slightly (so, it is a weak acid). is corrosive and irritating to the skin. It is best to say it is not soluble in water. + H 2 O + H 3 O + 39

40. Physical Properties… Would this derivative of phenol be water soluble? A) yesb) no

41. Remember, the cutoff is 5 carbons. Phenol has 6, and is not water soluble itself… A) yesb) no So ortho propyl phenol is not soluble b/c it has too many carbons.

42. Thiols are organic compounds that contain a –SH group. are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. 42

43. Naming Thiols In thiols with long carbon chains, the chain is numbered to give the −SH group the lowest possible number. 43

44. Sources of Thiols Thiols often have strong odors. are used to detect gas leaks. are found in onions, oysters, and garlic. 44

45. Try to name this thiol in your composition books… 45

46. Answer: This is 1-Propanethiol 46

47. Thiols are not soluble in water… Why?

48. Thiols are not soluble in water… Remember, you have to have an oxygen or nitrogen in the structure to be able to form hydrogen bonds with the water molecules…

49. Ethers Ethers consist of an oxygen atom that is connected by single bonds to two carbon groups (alkyl or aromatic). Simple ethers are named by listing the alkyl names in alphabetical order followed by ether 49 CH 3 ─ O ─ CH 3 CH 3 ─ CH 2 ─ O ─ CH 3 methyl ethylmethyl

50. IUPAC Names for Ethers In the IUPAC system, you can also name an ether as an attachment: it is named as an alkoxy group. Methoxy propane CH 3 —O—CH 2 —CH 2 —CH 3 1 2 3 50

51. IUPAC Names for Ethers Putting it together, you will get the name: CH 3 —O—CH 2 —CH 2 —CH 3 1 2 3 1-Methoxypropane. 51

52. Ethers as attachments Methoxy Ethoxy isopropoxy

53. Cyclic Ethers A cyclic ether contains an O atom in a carbon ring. is called a heterocyclic compound. Furan Tetrahydrofuran (THF) Pyran 53

54. Pick one to try to name & draw in your composition book…

55. Pick one to try to name & panel submit Isopropyl pheny ether Or Isopropoxy benzene Ethyl propyl ether Or 2-Ethoxy propane

56. Your Book’s Guide to Naming Ethers 56

57. Learning Check 57 Give the IUPAC name for the following. CH 3 —O—CH 2 —CH 2 —CH 2 —CH 2 —CH 3

58. Solution CH 3 —O—CH 2 —CH 2 —CH 2 —CH 2 —CH 3 1 2 3 4 5 1-methoxypentane is fine (or methyl pentyl ether) 58

59. Learning Check 59 Draw the condensed structural formula of each of the following compounds. A. 1-Ethoxypropane

60. Solution A. 1-Ethoxypropane CH 3 —CH 2 —O—CH 2 —CH 2 —CH 3 60

61. Learning Check 61 Draw the condensed structural formula of each of the following compounds… C. 2-Methoxybutane

62. Solution C. 2-Methoxybutane 62

63. Ethers as Anesthetics Early anesthetics, such as diethyl ether CH 3 ─ CH 2 ─ O ─ CH 2 ─ CH 3 worked by inhibiting pain signals to the brain. caused nausea and are flammable. 63

64. R–O–R ~ tetrahedral bond angle Oxygen is sp 3 -hybridized Oxygen atom gives ethers a slight dipole moment Not very reactive, so they make good solvents (diethyl ether is the “ether” we use in lab all the time). Not water soluble (although diethyl ether is slightly…see diagram on the following page)… Properties of Ethers

65. This is why you have to “dry” the organic layer in your reactions!

66. Solubility of Ethers in Water Ether Solubility in H 2 O 1–3 carbon atomsminorly soluble 4 carbon atomsslightly soluble (drops only) 5 or more carbon atomsinsoluble Ethers containing up to 4 carbon atoms are slightly soluble in water (they are really considered not soluble in water at all)… (So you should consider them NOT soluble in water!) 66

67. Which would be soluble in water?

68. Answer Of these, only Propanol is soluble in water! Ether…not phenol…notthiols…not

69. Draw an example of a compound that would be soluble in water in your composition book…

70. Boiling Points of Ethers Ethers have an O atom, but no H is attached. cannot form hydrogen bonds between ether molecules. have boiling points similar to alkanes of similar mass. 70

71. Learning Check Which compound would have the higher boiling point, ethyl methyl ether or 1-propanol? Explain. 71

72. Solution Which compound would have the higher boiling point, ethyl methyl ether or 1-propanol? Explain. 1-propanol has 3 carbon atoms, and can form hydrogen bonds with water giving it a higher boiling point. Ethyl methyl ether also has 3 carbons, but forms fewer hydrogen bonds with water due to its structure. 72

73. Learning Check Which compound would be more soluble in water, ethanol or 2-pentanol? Explain. 73

74. Solution Which compound would be more soluble in water, ethanol or 2-pentanol? Explain. Ethanol has 2 carbon atoms in its chain. It is more soluble than pentanol with 5 carbons. The longer the alkyl chain, the less soluble the alcohol in water. 74

75. Physical Properties Summary… M.p./b.p. Alcohols & phenols can hydrogen bond, so are high; thiols and ethers just have van der Waals forces, so are only a little above alkanes. Water solubility: Alcohols are water soluble. Thiols and ethers are not. Phenol is only soluble if it is in a basic solution. (so for the most part, only alcohols from this section are water soluble).

76. Reactions… Alcohol reactions are definitely tomorrow. One thiol reaction to know (let’s see what time it is though). We may just wait and do all of the reactions tomorrow.

77. A few reactions… For the most part, ethers are used as solvents because they are so unreactive! So the reaction that you need to know for ethers is just the reaction to make them from alcohols…

78. Making an ether… You can make an ether using an alcohol… (two molecules of alcohol).

79. Oxidation of Thiols When thiols undergo oxidation, an H atom is lost from two –SH groups. the product is a disulfide. disulfide 79

80. Practical Application… Much of the protein in hair is cross-linked by disulfide bonds, which occur between the thiol groups of the amino acid cysteine. 80

81. Practical Application… When a person gets a perm, a reducing substance is used to break the disulfide bonds. 81 Why is this considered a reduction?

82. Practical Application… You are adding hydrogen to the two sulfur atoms, so it is a reduction. 82

83. Problems for Additional Practice… Time permitting, we will go through some of these, but they are here just in case & you can check through them yourselves.

84. Learning Check Give the IUPAC name and degree for each of the following. 84 CH 3 —CH 2 —CH 2 —CH 2 —OH A. B.

85. Answers… 85 4 3 2 1 1 2 3 4 5 3-methyl-2-pentanol, secondary Butanol, primary CH 3 —CH 2 —CH 2 —CH 2 —OH A. B.

86. Practice… ab Give the name and degree of alcohol for one of the structures above in your composition book…

87. Practice… ab 7-methyl-3-octanol It is a 2 o alcohol 4-butyl-2-isopropyl-1-nonanol It is a primary alcohol

88. b 7-methyl-3-octanol 2-isopropyl-4-butyl-1-nonanol Recall rule 2 (the carbon with the OH gets priority) Recall rule 1: (the alcohol carbon has to be in the longest chain)

89. Learning Check Write the name of the following in your composition book… 89

90. Answer… This is ortho fluoro phenol 90

91. Learning Check 91 Draw the condensed structural formula of each of the following compounds. A. 2-Butanethiol B. 2-Methyl-1-butanol

92. Solution A. 2-Butanethiol B. 2-Methyl-1-butanol 92

93. Learning Check Try to name the following in your composition book…. A. B. 93

94. Solution A. Methoxy cyclopentane (cyclopentyl methyl ether) B. THF 94

95. Learning Check 95 Draw the condensed structural formula of each of the following compounds…. B. Ethyl methyl ether

96. Solution b. Ethyl methyl ether CH 3 —CH 2 —O—CH 3 96