1. CHE 242 Unit V Structure and Reactions of Alcohols, Ethers and Epoxides; Basic Principles of NMR Spectroscopy CHAPTER ELEVEN Terrence P. Sherlock Burlington County College 2004

2. Chapter 112 Types of Alcohol Reactions Dehydration to alkene Oxidation to aldehyde, ketone Substitution to form alkyl halide Reduction to alkane Esterification Tosylation Williamson synthesis of ether =>

3. Chapter 113 Summary Table =>

4. Chapter 114 1º, 2º, 3º Carbons =>

5. Chapter 115 Oxidation of 2° Alcohols 2° alcohol becomes a ketone Reagent is Na 2 Cr 2 O 7 /H 2 SO 4 Active reagent probably H 2 CrO 4 Color change: orange to greenish-blue =>

6. Chapter 116 Oxidation of 1° Alcohols 1° alcohol to aldehyde to carboxylic acid Difficult to stop at aldehyde Use pyridinium chlorochromate (PCC) to limit the oxidation. PCC can also be used to oxidize 2° alcohols to ketones. =>

7. Chapter 117 3° Alcohols Don’t Oxidize Cannot lose 2 H’s Basis for chromic acid test =>

8. Chapter 118 Alcohol as a Nucleophile ROH is weak nucleophile RO - is strong nucleophile New O-C bond forms, O-H bond breaks. =>

9. Chapter 119 Alcohol as an Electrophile OH - is not a good leaving group unless it is protonated, but most nucleophiles are strong bases which would remove H +. Convert to tosylate (good leaving group) to react with strong nucleophile (base) =>  + + C-Nuc bond forms, C-O bond breaks

10. Chapter 1110 Formation of Tosylate Ester p-toluenesulfonyl chloride TsCl, “tosyl chloride” ROTs, a tosylate ester =>

11. Chapter 1111 S N 2 Reactions of Tosylates With hydroxide produces alcohol With cyanide produces nitrile With halide ion produces alkyl halide With alkoxide ion produces ether With ammonia produces amine salt With LiAlH 4 produces alkane =>

12. Chapter 1112 Summary of Tosylate Reactions =>

13. Chapter 1113 Reduction of Alcohols Dehydrate with conc. H 2 SO 4, then add H 2 Tosylate, then reduce with LiAlH 4 =>

14. Chapter 1114 Reaction with HBr -OH of alcohol is protonated -OH 2 + is good leaving group 3° and 2° alcohols react with Br - via S N 1 1° alcohols react via S N 2 =>

15. Chapter 1115 Mechanism with PBr 3 P bonds to -OH as Br - leaves Br - attacks backside (S N 2) HOPBr 2 leaves =>

16. Chapter 1116 Reaction with Thionyl Chloride Produces alkyl chloride, SO 2, HCl S bonds to -OH, Cl - leaves Cl - abstracts H + from OH C-O bond breaks as Cl - transferred to C =>

17. Chapter 1117 Periodic Cleavage of Glycols Same products formed as from ozonolysis of the corresponding alkene. =>

18. Chapter 1118 Fischer Esterification Acid + Alcohol yields Ester + Water Sulfuric acid is a catalyst. Each step is reversible. =>

19. Chapter 1119 Tosylate Esters Alcohol + p-Toluenesulfonic acid, TsOH Acid chloride is actually used, TsCl =>

20. Chapter 1120 Sulfate Esters Alcohol + Sulfuric Acid =>

21. Chapter 1121 Nitrate Esters =>

22. Chapter 1122 Phosphate Esters =>

23. Chapter 1123 Phosphate Esters in DNA =>

24. Chapter 1124 Alkoxide Ions ROH + Na (or NaH) yields sodium alkoxide RO - + 1° alkyl halide yields ether (Williamson ether synthesis) =>

25. Chapter 1125

26. Chapter 1126 POWER POINT IMAGES FROM “ORGANIC CHEMISTRY, 5 TH EDITION” L.G. WADE ALL MATERIALS USED WITH PERMISSION OF AUTHOR PRESENTATION ADAPTED FOR BURLINGTON COUNTY COLLEGE ORGANIC CHEMISTRY COURSE BY: ANNALICIA POEHLER STEFANIE LAYMAN CALY MARTIN