Sodium Chloride → (1S)-[(2R)-(2,4-difluorophenyl)-2-oxiranyl]ethanol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of diethyl L(+)-tartrate (32.2 ml, 0.188 mole) in dry CH2Cl2 (5 L) is added activated 3A° molecular sieve powder (120 g) and cooled the mixture to -5 ° C. Added a solution of titanium (IV) isopropoxide (120 ml, 0.4 mole) followed by t-butyl hydroperoxide (312 ml of 5-6M solution in decane) and continue to stir at -5 ° C. for 25 minutes. To this mixture, a solution of crude 6a in CH2Cl2 (400 ml) is added and stirred for 12 hours at 5° C. Cooled the reaction mixture to -40° C., added 280 ml of 30% aq. NaOH solution saturated with NaCl and the mixture is allowed to warm to 10° C. Added 250 g of MgSO4, 80 g of celite and continued to stir at 10° C. for 30 minutes. The mixture is suction-filtered over celite. To the filtrate toluene (4 L) and 3 L of ether are added and insoluble material removed by filtration. The filtrate is evaporated under reduced pressure to give the crude 7a as oil.

Herkunft & Nachweise