1. Reactions of aldehydes and ketones : oxidation reduction nucleophilic addition 1)Aldehydes are easily oxidized, ketones are not. 2)Aldehydes are more reactive in nucleophilic additions than ketones.

2. alkanealcohol aldehyde ketone carboxylic acid oxidation reduction addition product nucleophilic addition

3. nucleophilic addition to carbonyl:

4. Mechanism: nucleophilic addition to carbonyl 1) 2)

5. Mechanism: nucleophilic addition to carbonyl, acid catalyzed 1) 2) 3)

6. Aldehydes & ketones, reactions: 1)Oxidation 2)Reduction 3)Addition of cyanide 4)Addition of derivatives of ammonia 5)Addition of alcohols 6)Cannizzaro reaction 7)Addition of Grignard reagents 8) (Alpha-halogenation of ketones) 9) (Addition of carbanions)

7. 1) Oxidation a)Aldehydes (very easily oxidized!) CH 3 CH 2 CH 2 CH=O + KMnO 4, etc.  CH 3 CH 2 CH 2 COOH carboxylic acid CH 3 CH 2 CH 2 CH=O + Ag +  CH 3 CH 2 CH 2 COO - + Ag Tollen’s test for easily oxidized compounds like aldehydes. (AgNO 3, NH 4 OH(aq)) Silver mirror

8. Ketones only oxidize under vigorous conditions via the enol.

9. b) Methyl ketones: test for methyl ketones Yellow ppt

10. 2) Reduction: a)To alcohols

13. Then + H +  alcohol

14. Reduction b) To hydrocarbons

16. 3) Addition of cyanide

17. 1) 2)

18. Cyanohydrins have two functional groups plus one additional carbon. Nitriles can be hydrolyzed to carboxylic acids in acid or base:

19. 4) Addition of derivatives of ammonia

20. 1) 2) 3)

22. melting points of derivatives ketonesbp semi-2,4-dinitro- oxime carbazonephenylhydrazone 2-nonanone195119 56 acetophenone202199 24060 menthone209189 14659 2-methylacetophenone214205 15961 1-phenyl-2-propanone216200 15670 propiophenone220174 19154 3-methylacetophenone220198 20755 isobutyrophenone222181 16394

23. 5) Addition of alcohols

27. 6)Cannizzaro reaction. (self oxidation/reduction) a reaction of aldehydes without α-hydrogens

28. Formaldehyde is the most easily oxidized aldehyde. When mixed with another aldehyde that doesn’t have any alpha- hydrogens and conc. NaOH, all of the formaldehyde is oxidized and all of the other aldehyde is reduced. Crossed Cannizzaro:

29. 7) Addition of Grignard reagents.

30. 1) 2)

31. #3 synthesis of alcohols. Used to build larger molecules from smaller organic compounds.

33. Aldehydes & ketones, reactions: 1)Oxidation 2)Reduction 3)Addition of cyanide 4)Addition of derivatives of ammonia 5)Addition of alcohols 6)Cannizzaro reaction 7)Addition of Grignard reagents 8) (Alpha-halogenation of ketones) 9) (Addition of carbanions)

34. Planning a Grignard synthesis of an alcohol: a)The alcohol carbon comes from the carbonyl compound. b)The new carbon-carbon bond is to the alcohol carbon. New carbon-carbon bond

35. “The Grignard Song” (sung to the tune of “America the Beautiful”) Harry Wasserman The carbonyl is polarized, the carbon end is plus. A nucleophile will thus attack the carbon nucleus. The Grignard yields an alcohol of types there are but three. It makes a bond that corresponds from “C” to shining “C.”

36. or

37. ROHRX -C=O RMgX R´OH HXMg ox. H2OH2O larger alcohol

38. Stockroom: alcohols of four-carbons or less: (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, 2-methyl-1-propanol.) benzene cyclohexanol any needed inorganic reagents or solvents.

39. Grignard synthesis of 4-methyl-2-pentanol from alcohols of four-carbons or less: Step one: determine the carbonyl compound and Grignard reagent that you would use: CH 3 CH 3 CHCH 2 CHCH 3 OH H2OH2O CH 3 CH 3 CHCH 2 MgBr + CH 3 CH=O Step two: show the syntheses of the Grignard reagent and the carbonyl compound from alcohols…

40. CH 3 HBr CH 3 Mg CH 3 CH 3 CHCH 2 OH CH 3 CHCH 2 Br CH 3 CHCH 2 MgBr H + K 2 Cr 2 O 7 CH 3 CH 3 CH 2 OH CH 3 CH=O CH 3 CHCH 2 CHCH 3 special cond. OH 4-methyl-2-pentanol

41. 2-phenyl-2-propanol

42. 1-methylcyclohexanol

43. cyclohexylmethanol

44. aldehydeRCOOHketone ROR alkyne alkene RH RX ROH Alcohols are central to organic syntheses

45. ROHRX -C=O RMgX R´OH HXMg ox. H2OH2O larger alcohol

46. Using the Grignard synthesis of alcohols we can make any alcohol that we need from a few simple alcohols. From those alcohols we can synthesize alkanes, alkenes, alkynes, alkyl halides, ethers, aldehydes, ketones, carboxylic acids… eg. Outline all steps in a possible laboratory synthesis of 3-methyl-1-butene from alcohols of four carbons or less. CH 3 CH 3 CHCH=CH 2

47. Retrosynthesis: alkenes, syntheses: 1. Dehydrohalogenation of an alkyl halide 2. Dehydration of an alcohol 3. Dehalogenation of a vicinal dihalide 4. Reduction of an alkyne Methods 3 & 4 start with compounds that are in turn made from alkenes.

48. Dehydration of an alcohol? CH 3 H + CH 3 CHCHCH 3 yields a mixture of alkenes OH CH 3 H + CH 3 CHCH 2 CH 2 -OH yields a mixture of alkenes E1 mechanism via carbocation!

49. Dehydrohalogenation of an alkyl halide? CH 3 KOH(alc) CH 3 CHCHCH 3 yields a mixture of alkenes Br CH 3 KOH(alc) CH 3 CH 3 CHCH 2 CH 2 -BrCH 3 CHCH=CH 2 only product E2 mechanism, no carbocation, no rearrangement

50. CH 3 HBr CH 3 CH 3 CHCH 2 CH 2 -OH CH 3 CHCH 2 CH 2 -Br 1 o alcohol, S N 2 mechanism, no rearrangement! CH 3 KOH(alc) CH 3 CH 3 CHCH 2 CH 2 -BrCH 3 CHCH=CH 2 Use the Grignard synthesis to synthesize the intermediate alcohol from the starting materials.

51. CH 3 PBr 3 CH 3 Mg CH 3 CH 3 CHCH 2 -OH CH 3 CHCH 2 Br CH 3 CHCH 2 MgBr K 2 Cr 2 O 7 CH 3 OH H 2 C=O special cond. H 2 O CH 3 CH 3 CHCH 2 CH 2 -OH HBr CH 3 KOH(alco) CH 3 CH 3 CHCH=CH 2 CH 3 CHCH 2 CH 2 -Br