Organic chemistry - Chapter 11: Aldehydes-ketone - Nam Phan

Nội dung text: Organic chemistry - Chapter 11: Aldehydes-ketone - Nam Phan

1. Chapter 11: ALDEHYDES-KETONES C=O C=C SP2 carbon 2
2. Lower priority than ester Æ “oxo” group 4
3. NOMENCLATURE OF KETONES Derived names: alkyls + ketone IUPAC names: hydrocarbon + one 6
4. PREPARATION OF ALDEHYDES & KETONES Aldehydes & ketones from alkenes In the presence of an oxidizing agent, the products will be ketones / carboxylic acids 8
5. Aldehydes & ketones from alcohols 10
6. Aldehydes from esters, acyl chlorides Note: LiAlH4 Æ alcohols 12
7. Gatterman-Koch synthesis of benzaldehyde Can NOT be prepared & isolated 14
8. Reactions with Grignard reagents Only for the reaction of HCHO 16
9. Reactions with acetylide ions Weak acid, will NOT react with the triple bond 18
10. Nitriles Æ carboxylic acids Nitriles Æ amines 20
11. Reaction mechanism: 22
12. Reaction mechanism: 24
13. Reactions with alcohols 26
14. Reactions with sulfur nucleophiles 28
15. • NaBH4 can reduce aldehyde, ketones, acyl chlorides, but NOT alkenes & alkynes • LiAlH4 is a stronger reducing agent than NaBH4, but NOT safe to use for aldehydes & ketones 30
16. Oxidation reactions Aldehydes are generally easier to oxidize than primary alcohols 32
17. REACTIONS OF ALDEHYDES & KETONES II – REATIONS AT α-C 34
18. Reaction mechanism: Nucleophilic additions Aldol additions occur more slowly with ketones 36
19. Aldol condensations sometimes occur under the aldol addition conditions without additional heating NOT isolated 38
20. Very strong base 40
21. The haloform reactions Only for methyl ketones 42