D. A. Evans Epoxidation of Acyclic Alcohols Chem 206 ■ Allylic Alcohols erythro m-CPBA Φ Estimate Reagent t-BuOOH/VO(acac)2 t-BuOOH/Mo(CO)6 62:38 120° m-CPBA 4050° t-BuOOH/ vO(acac)2 t-BuoOH / Mo(CO)6 ■RCo3 H Transition States:-120° -H Tsminor R2 Yield Ratio Oshima. Tetrahedron Lett 1982. 23 3387. HBu84%99:1 70%99:1 ■v(+) Transition States:Φ-45 MAjor 60% Eto OEt Eto OE threo Depezay, Tetrahedron Lett. 1978, 19, 2869 Ratio K Oshima Coworker O(acac)2 t-BuooH/VO(acac 86:14 Boeckman JACS 1977. 99. 2805 K B Sharpless Coworkers Tetrahedron Lett. 1979. 20. 4733 t-BuOOH/t-BUO)3Al 100:0 Me NHCONHPh NHCONHPh le NHCONHPh CH2Ch, 0C Roush, J.Org. Chem. 1987, 52, 5127 Diastereoselection= 95: 5Me OH Me Me Me Me OH C Me H C H Me C Me H OH C HO H Me H H O Me Me OH Me Me OH Me O C H Me C Me H C Me H OH C HO H Me Me OH Me O Me O Me Me OH H H Me Me OH R1 R2 SiMe3 OH OEt OH O O EtO Me Me Me Me O EtO O OH OEt OH Me HO t-BuOOH t-BuOOH t-BuOOH H OH Me Me O C5H11 OH SiMe3 R1 R2 O O NHCONHPh Ph Me Me Ph NHCONHPh O OEt OH O O EtO Me Me Me Me O EtO O OH OEt O Bu Me HO Me OH O O Me Me OH O R1 R2 SiMe3 OH Ph NHCONHPh O Me Reagent + t-BuOOH / (t-BuO) 64 : 36 3Al 29 : 71 64 : 36 t-BuOOH / VO(acac)2 m-CPBA Reagent Ratio t-BuOOH / Mo(CO)6 62 : 38 ■ Allylic Alcohols: D. A. Evans Epoxidation of Acyclic Alcohols Chem 206 ~ 120 ° 40-50 ° F Estimate 71 : 29 95 : 5 t-BuOOH / VO(acac)2 m-CPBA Reagent Ratio t-BuOOH / Mo(CO)6 84 : 16 threo erythro Reagent + ■ RCO3H Transition States: F ~ 120 ° TSminor TSmajor ■ V(+) Transition States: F ~ 45 ° TSminor TSmajor K. B. Sharpless & Coworkers Tetrahedron Lett. 1979, 20, 4733. K. Oshima & Coworkers Tetrahedron Lett. 1980, 21, 1657, 4843. t-BuOOH / (t-BuO) 100 : 0 3Al 86 : 14 95 : 5 t-BuOOH / VO(acac)2 m-CPBA Reagent Ratio t-BuOOH / Mo(CO)6 95 : 5 + Reagent threo erythro 70 % 84 % R Yield 1 99 : 1 99 : 1 R2 Ratio + VO(acac)2 Oshima, Tetrahedron Lett. 1982, 23, 3387. Depezay, Tetrahedron Lett. 1978, 19, 2869. only isomer VO(acac)2 60 % 60 % t BuOOH VO(acac)2 only isomer Boeckman, JACS 1977, 99, 2805. Diastereoselection = 7 : 1 60 % VO(acac)2 Roush, J. Org. Chem. 1987, 52, 5127. m-CPBA CH2Cl2 , 0 °C 75 % + Diastereoselection = 95 : 5 ● ● ● ● ● ● ● ● ● ● ● ● ●