A series of
4-alkyl-4-aminobut-2-enoic acids (2)-(5) has been prepared as conformationally
restricted analogues of GABA. The synthetic route which involved allylic bromination followed by displacement with ammonia
also gave vinyl glycine analogues (7)-(9) as readily purified by-products of
the reaction. The low biological activity in
vitro against GABA uptake, binding and enzyme systems of (E)-2-aminocyclohexylideneacetic acid (4)
and (E)-2-aminocyclopentylideneacetic acid (5) has been interpreted in terms of
steric hindrance by the ring-forming methylene groups at the particularactive sites concerned.
一系列
制备了一系列 4-烷基-4-氨基丁-2-烯酸 (2)-(5) 作为 GABA 的构象受限类似物。
限制的 GABA 类似物。合成路线包括烯丙基溴化,然后用氨置换
乙烯基甘氨酸类似物(7)-(9)。
反应的副产品。乙烯基甘氨酸类似物
(E)-2-氨基环己基亚基乙酸(4)和(E)-2-氨基环己基亚基乙酸(5)对 GABA 吸收、结合和酶系统的体外生物活性较低。
和 (E)-2-aminocyclopentylideneacetic acid (5) 的体外生物活性较低,这是因为
在有关的特定活性位点上,成环亚甲基的立体阻碍作用。