Appropriately protected optically active tetrahydropyridazine-3-carboxylic acid and hexahydropyridazine-3-carboxylic acid were prepared via ring closure of α-hydrazino- and δ-hydrazinopentanoates. Either optically active glutamic acid or an enantioselective catalytic hydrogenation was used to generate the chiral center. The numerous optically active intermediates are valuable starting materials for the synthesis of other unusual amino acids.
通过δ-
肼和δ-
肼戊酸酯的闭环反应,制备了适当保护的光学活性四氢
哒嗪-3-
羧酸和
六氢哒嗪-3-羧酸。光学活性谷
氨酸或对映体选择性催化加氢均可用于生成手性中心。这些具有光学活性的中间体是合成其他不常见
氨基酸的宝贵起始原料。