Further work on the regiospecific alkylation of histidine and imidazole derivatives is reported, including convenient preparations of N(α)-benzyloxycarbonyl-N(Ï)-benzyl-L-histidine and N(α)-benzyloxycarbonyl-N(Ï)-benzyloxymethyl-L-histidine, and a sequence of reactions enabling controlled exclusive alkylation of the least hindered im-nitrogen (tritylation, phenacylation, detritylation, alkylation, and finally dephenacylation with zinc/acetic acid) in 4(5)-alkylimidazoles.
报道了组
氨酸和
咪唑衍
生物的区域特异性烷基化的进一步工作,包括 N(α)-苄
氧基羰基-N(α)-
苄基-
L-组氨酸和 N(α)-苄
氧基羰基-N(α) 的方便制备)-苄
氧基
甲基-
L-组氨酸,以及一系列反应,能够在 4(5)-烷基
咪唑中对最小受阻的
氮进行受控排他烷基化(三
苯甲基化、
苯酰化、去三
苯甲基化、烷基化,最后用
锌/
乙酸进行去
苯酰化)。