Chemoselective Michael reactions on pyroglutamates. Expeditious synthesis of spiro-bis-γ-lactams as β-turn peptidomimetics
作者:Miguel F Braña、Marı́a Garranzo、Beatriz de Pascual-Teresa、Javier Pérez-Castells、Marı́a Rosario Torres
DOI:10.1016/s0040-4020(02)00437-4
日期:2002.6
from pyroglutamic acid, the synthesis of spiro-bis-γ-lactams, using as key step a chemoselective Michael reaction of pyroglutamates is reported. Thus, the reaction of N-BOC-l-methyl pyroglutamate with LiHMDS gives the enolates at C4 which react with several Michael acceptors. On the other hand, N-benzyl-l-methyl pyroglutamate reacts under the same conditions, to give the ester enolate which reacts with
据报道,以焦谷氨酸为原料,以焦谷氨酸的化学选择性迈克尔反应为关键步骤,从焦谷氨酸开始合成螺双-γ-内酰胺。因此,N -BOC-1-甲基焦谷氨酸与LiHMDS的反应得到在C4的烯醇化物,其与几个迈克尔受体反应。另一方面,N-苄基-1-甲基焦谷氨酸在相同条件下反应,得到酯烯酸酯,该酯烯酸酯与迈克尔受体反应,生成季铵化衍生物。双环螺内酰胺的合成是由于这些衍生物中存在的硝基还原而直接产生螺环化合物。这些最终化合物可以用作β-转弯模拟物,因为它们的扭角在II型和II'型β-转弯的范围内。