反应详情

The resulting (R)-1,4-dihydro-2,6-dimethyl-1-methoxymethyl-4-(3-nitrophenyl)-5-pivaloyloxymethoxycarbonyl-3-pyridinecarboxylic acid was treated with a 0.5 M solution of diazomethane in diethyl ether and then treated with a 10% potassium hydroxide solution in methanol. The resulting (S)-1,4-dihydro-2,6-dimethyl-1-methoxymethyl-4-(3-nitrophenyl)-5-methoxycarbonyl-3-pyridinecarboxylic acid (recrystallized) was reacted with phenyldiazomethane to obtain (R)-benzyl methyl 1,4-dihydro-2,6-dimethyl-l-methoxymethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate. As a result of HPLC (isopropanol/hexane=l/10) using CHIRALCEL OD, the optical purity was found to be 69% ee.