反应详情

At 0° C., 25.5 g of benzylamine are added dropwise within a period of 1 hour to a solution of 35.7 g of (R)-2-(4-nitrobenzenesulphonyloxy)-3-methoxycarbonyl-2-penten-4-olide in 250 ml of methylene chloride. The resulting benzylamine-p-nitrobenzenesulphonic acid salt is filtered off, and the filtrate is concentrated by evaporation, filtered over silica gel with toluene, and recrystallised from ether/petroleum ether. [α]D20 =+22° (3% in CHCl3), m.p. 68°-70° C., IR (CH2Cl2) 1752, 1678, 1632 cm-1.

1. filtrationThe resulting benzylamine-p-nitrobenzenesulphonic acid salt is filtered off
2. concentrationthe filtrate is concentrated by evaporation
3. filtrationfiltered over silica gel with toluene
4. customrecrystallised from ether/petroleum ether
5. custom[α]D20 =+22° (3% in CHCl3), m.p. 68°-70° C., IR (CH2Cl2) 1752, 1678, 1632 cm-1