THEME: Structure and chemical properties of carboxylic acids. Heterofunctional compounds.

1. LECTURE2 THEME: Structure and chemical properties of carboxylic acids. Heterofunctional compounds. Lecturer:Yevheniya. B. Dmukhalska

2. Plan • Nomenclature of carboxylic acids • Physical properties of carboxylic acids. • Classification of carboxylic acids • Methods of preparation of carboxylic acids • Chemical properties of carboxylic acids. • Heterofunctional compounds. • Hydroxy-acids, nomenclature, isomerism, chemical properties and specific reactions for hydroxy-acids. • Introduction of optical isomerous. Mirror (optical) isomerism. Asymmetric carbon atom. Properties of enantiomers.

3. Carboxylic acids Carboxylic acids are compounds whose characteristic functional group is the carboxyl group -COOH , example: • Common formula of carboxylic acid:

4. Nomenclature of carboxylic acids

5. Classification of carboxylic acids : 1. By the nature of hydrocarbon radical a) saturated acids; b) unsaturated acids c) aromatic acid 2. By the number of carboxyl groups a) monocarboxylic acids; b) dicarboxylic acids.

6. Saturated acids are acids, which have only simple bonds in molecule. Example: methanoic (formic) acid ethanoic (acetic) acid propanoic (propionic acid) acid stearic acid (octadecanoic acid) CH3-(CH2)16-COOH

7. Unsaturated acid is an acid, which has both as simple bonds and duble bonds in molecule. Example: CH2=CH-COOH

8. Aromatic acid is acid, which contain aromatic ring. Example: benzoic acid.

9. Monocarboxylic acid is acid, which has one carboxylic group in molecule. Example: acetic acid, formic acid, buthanic acid.

10. Dicarboxylic acid is acid, which has two carboxylic group in molecule. Example: oxalic acid, malonic acid.

11. The names of some saturated monocarboxylic acids

12. The names of some unsaturated monocarboxylic acids

13. The names of some dicarboxylic acids

14. Methods of preparation of carboxylic acids. • Oxidationofalkylbenzenes. • Oxidationofprimaryalcohols. • Oxidationofaldehydes.

15. 4. Synthesis of carboxylic acids by the hydrolysis of nitriles.

16. Properties of Carboxylic Acids Physical Properties of Carboxylic Acids

17. Solubility of carboxylic acids

18. Chemical properties of carboxylic acids.

19. Reduction reaction. Carboxylic acids are reduced toprimary alcohols by the powerful reducingagent lithium aluminum hydride.

22. Sodium butanoate Salt formation Magnesium acetate Calcium acetate

23. α-halogenation of carboxylic acids • ThismethodofαbrominationofcarboxylicacidsiscalledtheHell–Volhard–Zelinskyreaction.

24. Substitution of the Hydroxyl Group Except reaction 3

25. 1. ESTERIFICATION Thispagelooksatesterification - mainlythereactionbetweenalcoholsandcarboxylicacidstomakeesters.

26. 2. Formationofacylchlorides. Formationofacylchlorides. Thionylchloridereactswithcarboxylicacidstoyieldacylchlorides. • Reactionwithhalo-compounds:

27. 3. PreparationofAcidAnhydrides

28. 4. The formation amides.

29. Formation of the biuret and a biuret reaction • urea

30. Decarboxylation of carboxylic acids. The loss of a molecule of carbon dioxide from a carboxylic acid is known as decarboxylation.

33. 8. Carboxylic acid derivatives. These classes of compounds are classified as carboxylic acid derivatives.All may be converted to carboxylic acids by hydrolysis.

34. Functional groups are groups of atoms found within molecules that are involved in the chemical reactions characteristic of those molecules. There are mono-, poly- and heterofunctional group in the structure of organic compounds: Monofunctional group – contains only 1 functional group. C2H5—OH Polyfunctional group – contains several similar functional group. Heterofunctional group – contains several different functional group. Sphingosine

35. Biological role: • Heterofunctional compounds are widespread in the nature. They are in fruits and vegetable leafs. Also they are formed in body. So, the lactic acid is product of transformation glucose (glycolysis) in human body. A malic and citric acid formed in a cycle of tricarboxylic acids, which is also known as citric acid cycle or Krebs' cycle. Hydroxo acids such as: pyruvic acid, acetoacetic acid, oxaloacetic acid, -ketoglutaric acid are important in metabolism of carbohydrates.

36. Hydroxyacids Hydroxyacids are the derivatives of carboxyl acids that contain –OH group (1 or more). β α 2-hydroxypropanoic acid α-hydroxypropanoic acid

37. glycolic acid, hydroxyacetic acid, hydroxyethanoic acid tartaric acid α,α’-dihydroxysuccinic acid, 2,3-dihydroxybutandioic acid, lactic acid, α- hydroxypropanoic acid, 2- hydroxypropanoic acid malic acid, hydroxysuccinic acid hydroxybutanedioic acid citric acid, 2-hydroxy-1,2,3-propantricarboxylic acid

38. lactic acid Methods of preparation of hydroxyacids: • Hydrolysis of α-halogenoacids • Oxidations of diols and hydroxyaldehydes • Hydration of α,β-unsaturated carboxylic acids • Hydrolysis of hydroxynitriles (cyanohydrins) β-hydroxypropanoic acid

39. Physical and chemical properties of hydroxycarboxylicacid For physical properties of hydroxycarboxylic acids are colorless liquids or crystalline substance, soluble in water. Chemical properties: Carboxyl group can react forming: a) salts: sodium β-hydroxypropanoic acid

41. Ester formation: Methyl-β-hydroxypropanoate Methyl-β-methoxylpropanoat β-ethanoatepropanoic acid

42. c) Amides formation: II. –OH group reaction: a) hydrohalogens (HCl, HBr, HI, HF) b) can oxidize amide of β-hydroxypropanoic acid β-oxopropanoic acid

43. Related to heat of: 1. α-hydroxyacids lactic acid lactide 2. β-hydroxyacids 3. γ-hydroxyacids

44. Decomposition α-hydroxyacids Ethanal formic acid

45. Phenolacids are the derivatives of aromatic carboxyl acids that contain –OH group (1 or more). Phenolacids. salicylic acid, 2-hydroxybenzoic acid o-hydroxycinnamic acid 4-hydroxybenzoic acid 3,4,5-trihydroxybenzoic acid, gallic acid

46. Phenolacids are the derivatives of aromatic carboxyl acids that contain –OH group (1 or more). Decarboxylation

48. Representatives of hydroxyacids: Lactic acid is a trivial name because at first it was extracted from milk. It is present in yogurt, sour milk and other milk products. It can form in muscles during hard and prolonged work. Salts of milk acid are used in medicine. Malic acid. It is present in green apples and some berries. It takes part in biological processes in human organisms and organisms of other alive creatures. It is used in medicine for synthesis of some medical preparations. Tartaric acid . It is present in grape. It is used in medicine for synthesis of some medical preparations.

49. Citric acid. It is present in orange, lemon and other citric fruits. It takes part in biological processes in human organism.

50. Oxoacids To oxoacids include aldehydo- and ketonoacids. These compounds include in the structure of the carboxyl group, aldehyde functional group or ketone functional group. acetoacetic acid, 3-oxobutanoic acid, β-ketobutyric acid glyoxylic acid, oxoethanoic acid Pyroracemic (pyruvic)acid, 2-oxopropanoic acid oxalacetic acid, oxobutanedioic acid, ketosuccinic acid γ-ketovaleric acid, 4-oxopentanoic acid, levulinic acid ketoglutaric acid