1,4-dioate [(E)- and (Z)-2] were synthesized in two ways: (a) by elimination of hydrogen fluoride from di-tert-butyl beta,beta-difluoroaspartate under the influence of 1,5-diazabicyclo[4.3.0]non-5-ene and (b) by amination with the ammonium acetate of di-tert-butyl monofluorooxaloacetate (3), obtained via condensation of tert-butyl monofluoroacetate with di-tert-butyl oxalate. Reduction of 2 with sodium
(E)-和(Z)-二叔丁基2-
氨基-3-
氟-
2-丁烯-1,4-二酸酯[(E)-和(Z)-2]的合成方法有两种: a)在1,5-二
氮杂双环[4.3.0] non-5-ene的影响下,从β-二叔丁基β,β-二
氟天冬氨酸中消除
氟化氢,以及(b)通
过乙酸二
铵的胺化反应通过单
氟乙酸叔丁酯与
草酸二叔丁酯缩合获得叔丁基单
氟草酰乙酸酯(3)。用
氰基硼氢化钠还原2得到二叔丁基单
氟天冬氨酸的混合物,其中赤型异构体构成主要产物。该异构体(4a)的结构通过相应酸5a的X射线晶体分析确定。将5a酯化为β-甲酯6,然后进行
氨解,得到赤-β-
氟天冬酰胺(7)。