1. Chemistry 125: Lecture 71 April 20, 2011 Acids and Acid Derivatives Decarboxylation (J&F Ch. 17) Acyl Compounds (J&F Ch. 18) This For copyright notice see final page of this file

2. R-Li & LiAlH 4 (e.g. J&F Sec. 17.7f) stop at C=O?

3. Decarboxylation (e.g. J&F 17.7g) malonic acid  acid (concerted) OH 2 HO OH C O H O -CO 2 enol

4. R Kolbe Electrolysis -e--e- fast at 4K ! R R-RR-R R = CH 3 (Kolbe 1848) R = (~50% 1973) Decarboxylation (e.g. J&F 17.7g) or CO 2 as leaving group from XCO 2 - or RCO 2 (e.g. J&F pp. 859-861) H 2 O + carbonic acid NH 3 + carbamic acid

5. Decarboxylation (e.g. J&F 17.7g) or CO 2 as leaving group from XCO 2 - or RCO 2 (e.g. J&F pp. 859-861) RCO 2 Ag Br 2 RBr + AgBr + CO 2 “Hunsdiecker Reaction” RCO 2 H Ag 2 O R - Br R CO 2 Br 2 Patents 1936-44

6. Decarboxylation (e.g. J&F 17.7g) or CO 2 as leaving group from XCO 2 - or RCO 2 (e.g. J&F pp. 859-861) Published in 1861 RCO 2 Ag Br 2 RBr + AgBr + CO 2 “Hunsdiecker Reaction” RCO 2 H Ag 2 O ? 1833-1887 Tony award 1954 (Kismet) Alexander Porfiryevich Borodin KCN RC N RCO 2 H H2OH2O H + or HO -  R-MgBr Mg O=C=O RCO 2 MgBr + H+H+ “R + ” “R - ” A. Sdobnikov Patents 1936-44

7. Acid Derivatives (e.g. J&F Ch. 18) X: O RC N RC nitrile H 2 C=C=O ketene +3 +2 -2 H 3 C - CO 2 H +3 -3 H2OH2O R - CO 2 H +3 H2OH2O

8. 1681 CH 3 C O NH 2 CH 3 -C=O(X) strong & independent 1727 CH 3 C O H 1715 CH 3 C O CH 3 CH 3 C O OCH 3 17461806 CH 3 C O Cl + - + - + - n N  * C=O n O  * C-Cl n O  * C-OMe :: : C=O weakened by resonance C=O strengthened by resonance Spectroscopy (pp. 888-889)

9. acyclic anhydride in phaseout of phase % Transmission %T

10. out of phase cyclic imide in phase

11. X-X- O RC Interconversion of Acid Derivatives (e.g. J&F pp. 886, 890, Figs. 18.17,18.22) - Y-Y- Tetrahedral Intermediate (A/D substitution, rather than pentavalent transition state as in S N 2) or acid-catalyzed (as in Fischer esterification) Leaving Group Hierarchy Cl - R’CO 2 - R’O - R’ 2 N - differences reinforced by resonance stabilization: + - H2OH2O transesterification K ~1 (shift by law of mass action) -8 ~5 ~16 ~35 RCO 2 H SOCl 2 H H H H pK a

12. Saponification K>>1 K ~10 11 OR - O RC - HO - OR - RO - HO - H pK a ~5 pK a ~16 Lye KOH soapglycerine triglyceride (fat) “I ain’t afraid to wash my hair in it.” “That there lard eats the lye.”

13. Going All the Way to C-OH (e.g. J&F pp. 891, 898-9, 903 (C-NH 2 ) )

14. Stopping Part Way to Preserve C=O (e.g. J&F pp. 892-893 (Fig. 18.22); 900 (Fig 18.38))

15. Acidic / Basic Hydrolysis of RCN pp. 904-905 C-OH O

16. Acidic Hydrolysis of RCN

17. Basic Hydrolysis of RCN

18. Acyl Compounds from Ketene (J&F Sec. 18.11, p. 907) H 2 C=C=O Nu: HNu or H + catalyzed 93% pK a = 17 pK a = ~31 pK a = ~10 H 2 C=C=O H - SEt -80°, 3 days 75% Ph - N - CH 3 H EtOH / H 2 O H - OC(CH 3 ) 3 87% H+H+ pK a = ~35 (Nu = N) R3NR3N

19. Insertion into Acyl-R Bond

20. Munich 1896 Adolf v. Baeyer Victor Villiger

21. Baeyer-Villiger Reaction - 1900 (insert O) (e.g. J&F pp. 907-909)

22. End of Lecture 71 April 20, 2011 Copyright © J. M. McBride 2011. Some rights reserved. Except for cited third-party materials, and those used by visiting speakers, all content is licensed under a Creative Commons License (Attribution-NonCommercial-ShareAlike 3.0).Creative Commons License (Attribution-NonCommercial-ShareAlike 3.0) Use of this content constitutes your acceptance of the noted license and the terms and conditions of use. Materials from Wikimedia Commons are denoted by the symbol. Third party materials may be subject to additional intellectual property notices, information, or restrictions. The following attribution may be used when reusing material that is not identified as third-party content: J. M. McBride, Chem 125. License: Creative Commons BY-NC-SA 3.0