Reacción #77924

Ecuación de reacción

dibenzyl L-aspartate paratoluenesulfonate

dibenzyl L-aspartate paratoluenesulfonate

phosphoric acid

sodium hydroxide

methanol

→

Dibenzyl Aspartate

Disolventes

chloroform

chloroform

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroNext, the chloroform layer was separated, to which
2. 2
   workup.STIRRINGagain stirred at room temperature for 2 hours
3. 3
   OtroIts chart gave two peaks

Procedimiento

19.4 g of the thus-obtained dibenzyl L-aspartate paratoluenesulfonate was suspended in 150 ml of chloroform, to which was added 16 g (0.04 mols) of aqueous 10% sodium hydroxide solution, and stirred at room temperature for 1 hour. Next, the chloroform layer was separated, to which was added 14.7 g (0.04 mols) of O,O′-diparatoluoyl-L-tartaric anhydride, and again stirred at room temperature for 2 hours. The chloroform layer was analyzed through HPLC. Its chart gave two peaks based on O,O′-diparatoluoyl-L-tartaric acid mono-L-(1,2-dibenzyloxycarbonyl)ethylamide (L-L form) of formula (16) and on O,O′-diparatoluoyl-L-tartaric acid mono-D-(1,2-dibenzyloxycarbonyl)ethylamide (L-D form) of formula (17), and the optical purity of the dibenzyl L-aspartate paratoluenesulfonate used in the reaction was found to be 59.0% ee (FIG. 1—column, CAPCELL PAC SG120; eluent, aqueous phosphoric acid solution (pH 2.2)/methanol=38/62 v/v).

Fuente