Sodium Chloride → (2S,3R)-1,2-Epoxy-2-(2,4-difluorophenyl)butan-3-ol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of diethyl L(+)-tartrate (16 ml, 0.094 mole) in dry CH2Cl2 (2.4 L) is added activated 3A° molecular sieve powder (600 g) and cooled the mixture to -5° C. Added a solution of titanium (IV) isopropoxide (59 ml, 0.20 mole) followed by t-butyl hydroperoxide (156 ml of 5-6M solution in decane) and continue to stir at -5° C. for 25 minutes. To this mixture, a solution of crude 6b, in CH2Cl2 (200 ml) is added and stirred for 12 hours at 5° C. Cooled the reaction mixture to -40° C., added 140 ml of 30% aq. NaOH solution saturated with NaCl and the mixture is allowed to warm to 10 °C. Added 120 g of MgSO4, 40 g of celite and continued to stir at 10° C. for 30 minutes. The mixture is suction-filtered over celite. To the filtrate toluene (2 L), and 1.5 L of ether re added and insoluble material removed by filtration. The filtrate is evaporated under reduced pressure to give the crude 7c as a light brown oil.

Herkunft & Nachweise