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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of diethyl L(+)-tartrate (161 ml, 0.94 mole) in dry CH2Cl2 (24 L) was added activated 3A° molecular sieve powder (600 g) and cooled the mixture to -5° C. Added a solution of titanium (IV) isopropoxide (597 ml, 2.0 mole) followed by t-butyl hydroperoxide (1.56 L of 5-6M solution in decane) and continue to stir at -5° C. for 25 minutes. To this mixture, a solution of crude 6a, (664 g) in CH2Cl2 (2 L) was added and stirred for 12 hours at 5° C. Cooled the reaction mixture to -40° C., added 1.4 L of 30% aq. NaOH solution saturated with NaCl and the mixture was allowed to warm to 10° C. Added 1.2 kg of MgSO4, 400 g of celite and continued to stir at 10° C. for 30 minutes. The mixture was suction-filtered over celite. To the filtrate toluene (20 L), and 15 L of ether were added and insoluble material removed by filtration. The filtrate was evaporated under reduced pressure to give the crude 7a as a light brown oil (740 g).

Herkunft & Nachweise