Stereoselective synthesis of the imidazole alkaloids (+)-pilocarpine and (+)-isopilocarpine. (Imidazole chemistry, Part IX)

✍ Scribed by A. Noordam; L. Maat; H. C. Beyerman

• Book ID: 104588389
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 727 KB
• Volume: 100
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19811001202

✦ Synopsis

Abstract

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 which is well established.