Stereoselective synthesis of the imidazole alkaloids (+)-pilocarpine and (+)-isopilocarpine. (Imidazole chemistry, Part IX)
作者:A. Noordam、L. Maat、H. C. Beyerman
DOI:10.1002/recl.19811001202
日期:——
A novel synthesis of (+)-pilocarpine (10a) is described. L-Histidine is converted into methyl (R)-2-bromo-3-(l-methyl-5-imidazolyl)propionate (5) in which the configuration has been inverted. Alkylation of dibenzyl ethylmalonate with 5 yields the imidazole compound 6, again with inversion. Finally, 6 is converted into a mixture of (+)-pilocarpine (10a) and (+)-isopilocarpine (10b), the separation of
描述了(+)-pilocarpine(10a)的新型合成。L-组氨酸被转化成(R)-2-溴-3-(1-甲基-5-咪唑基)丙酸甲酯(5),其构型已被反转。丙二酸乙基二苄酯与5的烷基化反应再次生成咪唑化合物6。最后,6被转化成(+)的混合物-毛果芸香碱(10A)和(+) - isopilocarpine(10B),其中所述分离是公认的。