A Lewis acid-catalysed diastereoselective [4 + 2] cycloaddition of vinylindoles and methyl 2-acetamidoacrylate, leading to methyl 3-acetamido-1,2,3,4-tetrahydrocarbazole-3-carboxylate derivatives, is described. Treatment of the obtained cycloadducts under hydrolytic conditions results in the preparation of a small library of compounds bearing the free amino acid function at C-3 and pertaining to the class of constrained tryptophan analogues.
一种
路易斯酸催化的对映选择性[4 + 2]环加成反应,涉及
乙烯基吲哚和甲基
2-乙酰氨基丙烯酸酯,生成甲基
3-乙酰氨基-1,2,3,4-四氢咔唑-3-
羧酸酯衍
生物。在
水解条件下处理所得的环加成产物,可制备一系列具有C-3上自由
氨基酸功能的化合物库,属于约束色
氨酸类似物。