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Chapter 7 Alcohols, Ethers, and Epoxides

Chapter 7 Alcohols, Ethers, and Epoxides. ( 醇、醚、环氧化物 ) Text 1: Chapter 10, 11, 14. I. Alcohol ( 醇 ). The origins of alcohols Ethyl alcohol (ethanol): grain alcohol （酒精） Methyl alcohol (methanol): wood alcohol （木醇） Role of alcohols Reagents Solvents

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Chapter 7 Alcohols, Ethers, and Epoxides

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  1. Chapter 7Alcohols, Ethers, and Epoxides (醇、醚、环氧化物) Text 1: Chapter 10, 11, 14

  2. I. Alcohol (醇) • The origins of alcohols • Ethyl alcohol (ethanol): grain alcohol（酒精） • Methyl alcohol (methanol): wood alcohol（木醇） • Role of alcohols • Reagents • Solvents • Synthetic intermediates (合成中间体)

  3. sp3 sp2 sp3 sp3 sp2 1. Structure of alcohols ethanol 乙醇 methanol 甲醇 Phenol 苯酚 tautomerism 互变异构 Enol (烯醇) Aldehyde (醛)

  4. tertiary alcohol (叔醇) 3° secondary alcohol (仲醇) 2° primary alcohol (伯醇) 1° 2. Classification of alcohols • According to the type of carbinol carbon atom alcohols can be classified as follows:

  5. 3. Nomenclature of Alcohols IUPAC names: alkane alkanol alkylalcohol Common names: 中文: XX醇 ethanol (ethyl alcohol) 乙醇 2-propanol propan-2-ol (isopropyl alcohol) 2-丙醇; 异丙醇 methanol (methyl alcohol) 甲醇

  6. 1-butanol butan-1-ol (n-butyl alcohol) 1-丁醇; (正丁醇) 2-butanol butan-2-ol (sec-butyl alcohol) 2-丁醇; (仲丁醇) 2-methyl-1-propanol 2-methylpropan-1-ol iso-butyl alcohol 2-甲基-1-丙醇; (异丁醇) 2-methyl-2-propanol 2-methylpropan-2-ol t-butyl alcohol 2-甲基-2-丙醇; (叔丁醇)

  7. The order of precedence of functional groups for assigning IUPAC names Acids Esters Aldehydes Ketones Alcohols Amines Alkenes Alkynes Alkanes Ethers Halides Decreasing priority 4-penten-2-ol pent-4-en-2-ol 4-戊烯-2-醇 2-hydroxy-3,3-dimethylbutanal 2-羟基-3,3-二甲基丁醛

  8. phenylmethanol (benzyl alcohol) 苯甲醇 苄(基)醇 2-propenol (allyl alcohol) 2-丙烯醇 烯丙醇 2-propynol 2-丙炔醇 炔丙醇 cyclohexanol 环已醇 trans- 2-bromocyclohexanol (1R,2R)-2-bromocyclohexanol

  9. Names of diols butane-2,3-diol 2,3-丁二醇 ethane-1,2-diol (ethylene glycol) 乙二醇 glycol (甘醇)= 1,2-diol = vicinal diol, 邻位二醇

  10. Names of phenols 4-bromophenol (para-bromophenol) 4-溴苯酚 对溴苯酚 2-bromophenol (ortho-bromophenol) 2-溴苯酚 邻溴苯酚 3-bromophenol (meta-bromophenol) 3-溴苯酚 间溴苯酚 o-, m-, p- 邻, 间, 对

  11. hydrophobic region 疏水区 hydrophilic region 亲水区 4. Physical properties of alcohols Boiling points: Alcohols have much higher boiling points than ethers or hydrocarbons having similar molecular weight. Solubility: C1-3, miscible with water.

  12. Problem 10-34 Predict which member of each pair has the higher bp, and explain the reasons for your predictions. • 1-hexanol or 3,3-dimethyl-1-butanol • 2-hexanone or 2-hexanol • 2-hexanol or 1,5-hexanediol • 2-pentanol of 2-hexanol

  13. Methanol Important alcohols Ethanol Methanol is highly toxic,it can cause blindness or death.

  14. 5. Synthesis of alcohols 1) Synthesis of alcohol from alkyl halide SN2 reaction 2) Synthesis of alcohols from alkenes (A) Hydration of alkenes C+ intermediate

  15. (B) oxymercuration-Demercuration(羟汞化－脱汞) anti addtion follow Mar’s rule

  16. (C) Hydroboration-oxidation (硼氢化-氧化反应) syn addition anti Mar’s product

  17. Problem: (10-37) Show how you would synthesize the following alcohols from appropriate alkenes.

  18. 3) Synthesis of alcohols from carbonyl compounds(由羰基化合物制醇） carbonyl group 羰基 aldehyde 醛 ketone 酮 carboxylic ester 羧酸酯 carboxylic acid 羧酸

  19. Nu:- alkoxide ion Nucleophilic addition (亲核加成)

  20. (A) Reaction of carbonyl compounds with organometallic reagents to give alcohols alkynol (炔醇)

  21. Organometallic compounds（有机金属化合物） Compounds that contain carbon-metal bonds (C-M) are called organometallic compounds. (a) great important in organic synthesis; (b) relatively stable in ether solutions. (a) highly reactive Nu; (b) powerful B.

  22. (a) much less reactive; (b) often volatile (挥发性的) and are stable in air; (c) all poisonous; (d) generally soluble in nonpolar solvents. Tetraethyllead has been used as an "antiknock" compound in gasoline.

  23. Preparation of organolithium and organomagnesium compounds The order of reactivity of halides is: RI > RBr > RCl Organolithium compounds (有机锂化合物）

  24. Grignard reagents （格利雅试剂, 格氏试剂）

  25. Grignard reagents are stable in ether

  26. Preparation of alcohols by the addition of Grignard reagents to carbonyl compounds Nucleophilic addition

  27. Acetaldehyde 乙醛

  28. Grignard reagent Grignard reagent ester ketone tertiary alcohol

  29. Organolithium reagents (RLi) react with carbonyl compounds in the same way as Grignard reagents.

  30. Attention!!! Side reactions of organometallic reagents 体系中不能有活泼氢, 如 O-H, N-H, S-H, -C≡C-H; 底物中不能含有其它极性多重键,如 C=O, C=N, C≡N, S=O, N=O.

  31. X

  32. 2) Reduction of carbonyl compounds to give alcohols (10-11, 11-1)

  33. LiAlH4 lithium aluminum hydride 氢化铝俚，四氢铝锂　 NaBH4 sodium borohydride 硼氢化钠 (A) LiAlH4 aldehydes ketones acids esters NaBH4 hydride transfer nucleophile addition

  34. fast LiAlH4 + H2O H2 + LiOH + Al(OH)3 slow NaBH3 + H2O H2 + NaOH + B(OH)3 LiAlH4: dry Et2O, THF as solvents NaBH4: EtOH, MeOH, etc. as solvents

  35. (B) Catalytic hydrogenation of aldehydes and ketones

  36. Problems: give the main products.

  37. Summary for alcohols synthesis • Synthesis of alcohol from: • alkenes • acid-catalyzed hydration (酸催化的水化反应) • hydroboration-oxidation (硼氢化反应) • oxymercuration-demercuration (汞氧化反应) • hydroxylation (羟化反应) to prepare 1,2-diols • carbonyl compounds • addition of Grignard reagents • reduction with NaBH4 and LiAlH4 • alkyl halides

  38. Assignments Text 1: 10-31, 33, 38, 44, 49

  39. 7. Reactions of alcohols • Oxidation (氧化) • substitution • dehydration (脱水) • Esterification （酯化）

  40. 1) Oxidation of alcohols (11-1, 2, 3) Oxidation-Reduction reactions in organic chemistry • Reduction (还原)of an organic molecule usually corresponds toincreasing its hydrogen contentor todecreasing its oxygen content.(加氢、去氧或去卤素, 增加Ｃ－Ｈ键数或减少Ｃ－Ｏ键数) • Oxidation (氧化): increasing the oxygen content of an organic molecule or decreasing its hydrogen content.(加氧或加卤素、去氢，减少Ｃ－Ｈ键数或增加Ｃ－Ｏ键数)

  41. C-O, 3→2 C-O, 2→1 C-O, 1→0

  42. Problem 11-1 p 446

  43. Tertiary alcohols Primary alcohols aldehydes carboxylic acids Secondary alcohols ketones difficult to be oxidized.

  44. (A) Oxidization with Cr(VI) (11-2) • Oxidants: • K2Cr2O7 or Na2Cr2O7 / H2SO4 • CrO3/ H2SO4 butyric acid

  45. Mechanism of chromate oxidations （铬酸氧化机理）

  46. Or

  47. A Chemical test for 1°, 2°, and 3° alcohols Reagent: CrO3 / aqueous H2SO4 or Na2Cr2O7 / aqueous H2SO4

  48. PCC (Pyridinium chlorochromate, 吡啶三氧化铬) PDC (Pyridinium dichromate, 重铬酸吡啶盐)

  49. Oxidation with KMnO4, or HNO3 (11-3) If the conditions are not controlled, KMnO4 or HNO3 will cleave the carbon-carbon bonds.

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