Page 103 - Catalysts for Fine Chemical Synthesis Vol 1 - Robert & Poignant

unfunctionalized alkenes a, b-unsaturated esters 89

There seems to be a direct attack of alkene at the oxometal, with C±O bond
formation (Figure 6.2).

6.1.1 EPOXIDATION OF (Z)-METHYL STYRENE [3]

(S,S) catalyst(5 mol%) O
+ NaOCl(aq)
Ph Me CH 2 Cl 2 Ph Me
(1S,2R)

Materials and equipment
. Jacobsen's catalyst ((S,S)-(ÿ)-N, N -bis (3,5-di-tert-butylsalicylidene)-1,2-
0
cyclohexanediaminomanganese(III) chloride, 98 %), 26 mg, 0.04 mmol,
0.04 eq
. (Z)-Methyl styrene, 1 mmol
(Z)-Methyl styrene was easily obtained by hydrogenation of l-phenyl-
l-propyne using Lindlar's catalyst (5 % palladium on calcium carbonate,
poisoned with lead) in n-hexane under an atmospheric pressure of hydrogen.
The mixture, containing 90 % of (Z)-methyl styrene and 10 % of the over-
reduced alkane, was used without further purification.
. Sodium hydrogenphosphate aqueous solution, 0.05 M, 5 mL
. Bleach (sodium hypochlorite, available chlorine 14 %), 2.5 mL
. Sodium hydroxide solution, 1 M
. Hydrogen chloride solution, 1 M
. Dichloromethane, n-hexane, petroleum ether, diethyl ether, ethyl acetate,
triethylamine
. Brine
. Sodium sulfate
. Silica gel 60 (0.063±0.04 mm)
. p-Anisaldehyde

. 100 mL Round-bottomed flask with a magnetic stirrer bar
. Magnetic stirrer
. Beaker, 100 mL
. Separating funnel, 100 mL
. Rotary evaporator
. pH-meter

Procedure
1. A solution was prepared by mixing an aqueous solution of sodium hydro-
genphosphate (0.05 M, 5 mL) and a solution prepared with concentrated