1. Oxidation 1. Oxidation of Alcohol a. Cr oxidation : Mechanism

2. i) Jone’s reagent : CrO 3 + H 2 SO 4 + acetone --- acidic No racemization ii) Collins reagent : CrO 3 + pyridine --- basic iii) PCC : CrO 3 + HCl + pyridine --- acidic iv) PDC : CrO 3 + 2 pyridine --- less acidic

3. b. Mn oxidation : i) KMnO 4 : solubility problem, over-oxidation problem ii) MnO 2 : mild oxidant, requires activation R is only benzylic or allylic c. Ru oxidation : i) RuO 4 : RuO 2 + oxidants( IO 4 -, NaOCl)

4. ii) TPAP : Pr 4 NRuO 4 -- catalyst + oxidants( NMO) c. Activated sulfides : i) Moffatt oxidation : DMSO + DCC Suitable for 1,2-diol oxidation : cf.) metal oxidants cleave C-C bond

5. ii) Swern oxidation : DMSO + oxallyl chloride + Nt 3 N iii) Corey-Kim : DMS + NCS d. Dess-Martin reagent : periodinane – most mild but strong oxidant Moisture sensitive

6. 2. Oxidation of Aldehyde Not so reliable Reliable, not scalable Mechanism based Org. Lett. 5, 2003, 1031

7. Unusual oxidizing agents Mostly lactol oxidation

8. Unusual oxidizing agents

9. 3. Epoxidation of olefin Becomes more reactive with electron withdrawing R Most popular a. Peracid : electrophilic reagent b. HOONa : nucleophilic reagent More substituted one reacts faster, Electron donating group accelerates the reaction Mechanism

10. c. dioxirane Generation : Ketone + oxone d. Sharpless epoxidation I. : selective oxidation of allylic alcohols t-BuOOH + VO(acac) 2 or Mo(CO) 6

11. e. Asymmetric epoxidation i) Sharpless epoxidation II. : t-BuOOH + Ti(Oi-Pr) 4 + tartarate ester When R 1 is small e.e. > 90% Mechanism? : see Org. Rxn. V48, 1 (1996)

12. ii) Jacobsen epoxidation : catalyst + NaOCl Mechanism catalyst Jacobsen’s early proposal

13. ii) Jacobsen epoxidation : catalyst + NaOCl Mechanism catalyst

14. e. Asymmetric epoxidation iii) Chiral dioxirane : catalyst reagent

15. e. Asymmetric epoxidation iv) Conjugated system : JACS 2001, 123, 9474 Cat. = La(OiPr) 3 - BINOL-Ph 3 As=O TL 2006, 47, 99

16. 3. dihydroxylation of olefin OsO 4 : i) Stoicheometirc or catalytic with N-oxides Cis- diol ii) Asymmetric dihydroxylation

17. 3. dihydroxylation of olefin ii) Asymmetric dihydroxylation 95% e.e. JACS 1987, 109, 6213

18. iii) Catalytic asymmetric dihydroxylation

19. iv) Catalytic asymmetric aminohydroxylation

20. 5.cleavage of olefin a. ozonolysis : O 3 electrophilic reagent -- not a clean reaction

21. 6. allylic oxidation of olefin b. Oxidation through diol : - IO 4 a. Singlet oxygen Ene reaction --- allylic transposition c. Direct oxidation with OsO 4 JACS, 124, 2002, 3824

22. 6. allylic oxidation of olefin b. SeO 2 With t-BuOOH, catalytic SeO 2 Regio, stereo-selectivity

23. 6. allylic oxidation of olefin c. CrO 3 via

24. Homework Chapter 12 : 1, 2, 4, 9 Due :