反应详情

13.2 g of diethyl azodicarboxylate were added dropwise to a solution of 20.7 g of triphenylphosphine in 300 ml of benzene and the mixture was stirred at room temperature for 30 minutes. At the end of this time, 35.0 g of 5-(4-hydroxybenzyl)-3-triphenylmethylthiazolidine-2,4-dione [prepared as described in step (d) above] were added to the mixture, and the resulting mixture was stirred at room temperature for 1 hour. 13.2 g of (R)-2-t-butoxycarbonylamino-1-propanol were added to the mixture, which was then allowed to stand overnight. At the end of this time, 40.9 g of triphenylphosphine, 23.68 ml of diethyl azodicarboxylate and 33 g of (R)-2-t-butoxycarbonylamino-1-propanol were added to the reaction mixture, in that order, in 3 or 4 separate portions, and the mixture was then stirred for 2 days. After this time, the benzene solvent was removed from the reaction mixture by distillation under reduced pressure, and the residue was purified by column chromatography through silica gel, using a 1: 3 by volume mixture of ethyl acetate and hexane as the eluent, to give 30 g of the title compound as crystals, melting at 153°-157° C.

1. stirringthe resulting mixture was stirred at room temperature for 1 hour
2. waitto stand overnight
3. customseparate portions
4. stirringthe mixture was then stirred for 2 days
5. customAfter this time, the benzene solvent was removed from the reaction mixture by distillation under reduced pressure
6. customthe residue was purified by column chromatography through silica gel
7. additionby volume mixture of ethyl acetate and hexane as the eluent