Total syntheses of (±)-cis- and trans-11-methoxydeethyleburnamonine

✍ Scribed by Kalle Rönkkö; Mathias Berner; Reija Jokela; Arto Tolvanen

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2000
• Tongue: English
• Weight: 302 KB
• Volume: 37
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570370520

✦ Synopsis

Abstract

The total syntheses of 11‐methoxydeethyleburnamonines (4) and (13) were carried out with use of 6‐methoxytryptophyl bromide (5) as starting material. Compound 5 was converted in three steps to trans‐ester 8. Acid‐catalysed epimerization of 8, lithium aluminum hydride reduction of the ester group, tosylation and substitution with cyanide gave the cis‐nitrile 12. Acid‐induced cyclization of 12 yielded mainly (±)‐trans‐11‐methoxydeethyleburnamonine (13), whereas base‐induced cyclization gave (±)‐cis‐11‐methoxydeethyleburnamonine (4).