TEMA PARA LA MATERIA DE QUÍMICA...t/t

1. Organic Chemistry
4th Edition
QBA Miguel A. Castro Ramírez
Chapter 18
Carbonyl
Compounds II
Radicals
Irene Lee
Case Western Reserve
University
Cleveland, OH

2. Nomenclature of Aldehydes

3. If the aldehyde group is attached to a ring,

4. If a compound has two functional groups, the one with the
lowest priority is indicated by its prefix

5. Nomenclature of Ketones

7. If a ketone has a second functional group of higher
priority,

8. An aldehyde has a greater partial positive charge on its
carbonyl carbon than does a ketone

9. • Steric factors contribute to the reactivity of an aldehyde
• The carbonyl carbon of an aldehyde is more accessible
to the nucleophile
• Ketones have greater steric crowding in their transition
states, so they have less stable transition states

10. Aldehydes and ketones react with nucleophiles to form
addition products: nucleophile addition reactions

12. If the nucleophile that adds to the aldehyde or ketone is
an O or an N, a nucleophilic addition–elimination reaction
will occur

13. Formation of a New Carbon–Carbon
Bond Using Grignard Reagents
Grignard reagents react with aldehydes, ketones, and
carboxylic acid derivatives

16. Reaction with Acetylide Ions

17. Reduction by Hydride Ion

20. Utilization of DIBAL to Control the
Reduction Reaction

21. The reduction of a carboxylic acid with LiAlH4 forms a
single primary alcohol
Acyl chloride is also reduced by LiAlH4 to yield an alcohol

22. An amide is reduced by LiAlH4 to an amine

23. Aldehydes and ketones react with a primary amine to
form an imine
This is a nucleophilic addition–elimination reaction
The pH of the reaction must be controlled

24. Dependence of the rate of the reaction of acetone with
hydroxylamine on the pH of the reaction: a pH rate profile

25. Aldehydes and ketones react with secondary amines to
form enamines

26. Formation of Imine Derivatives

27. Deoxygenation of the Carbonyl Group

28. Water adds to an aldehyde or ketone to form a hydrate

30. Why is there such a difference in the Keq values?

31. The equilibrium constant for the reaction depends on the
relative stabilities of the reactants and products

32. Addition of an Alcohol to an Aldehyde
or a Ketone

33. Utilization of Protecting Groups in
Synthesis
LiAlH4 will reduce the ester to yield an alcohol, but
the keto group will also be reduced

34. The keto group is protected as a ketal in this synthesis

35. The more reactive aldehyde is protected with the diol
before reaction with the Grignard reagent

36. • The OH group in an alcohol can be protected as a
trimethylsilyl ether
• The OH group in a carboxylic acid can be protected as
an ester
• An amino group can be protected with an acetyl group

37. Addition of Sulfur Nucleophiles

38. Desulfurization replaces the C–S bonds with C–H bonds

39. Formation of Alkenes
The Wittig Reaction

41. Preparation of the Phosphonium Ylide
If two sets of reagents are available for the synthesis of
an alkene, it is better to use the one that requires the less
sterically hindered alkyl halides

42. • The Wittig reaction is completely regioselective
• This reaction is the best way to make a terminal alkene
• Stable ylides form primarily E isomers, and unstabilized
ylides form primarily Z isomers
• Stable ylides have a group (C=O) that can share the
carbanion’s negative charge

43. Stereochemistry of Nucleophilic
Addition Reaction

51. • Nucleophiles that form unstable addition products form
conjugated addition products, because the conjugate
addition is not reversible
• Nucleophiles that form stable addition products can
form direct addition products or conjugate addition
products
• If the rate of direct addition is slowed down by steric
hindrance, a Grignard reagent will form the conjugate
addition product

52. Nucleophilic Addition to α,β-Unsaturated
Carboxylic Acid Derivatives

53. Enzyme-Catalyzed Additions to α,β-
Unsaturated Carbonyl Compounds