Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Paper | Regular issue | Vol 75, No. 1, 2008, pp.65-76
Published online, 14th September, 2007
DOI: 10.3987/COM-07-11172
Synthesis of Vinca Alkaloids and Related Compounds. Part 109. An Intramolecular [4+2] Cycloaddition Mediated Biomimetic Synthesis of (±)-Iboxyphylline

Flórián Tóth, György Kalaus*, Gergely Pipa, István Greiner, Áron Szollosy, Attila Rill, Ágnes Gömöry, László Hazai, and Csaba Szántay

*Faculty of Chemical Engineering, Budapest University of Technology and Economics, 1111 Budapest, Szt. Gellért tér 4, Hungary

Abstract

The pentacyclic alkaloid 1 could be synthesized by an intramolecular [4+2] cycloaddition reaction of intermediate 11, which had been obtained from tryptamine derivative 4 and aldehyde 5. After full epimerization of 13 the cyclization reaction furnished a mixture of 14a and 14b. Separation of the stereoisomers 14a and 14b and subsequent reduction with LiAlH4 resulted in (±)-iboxyphylline (14a 1) and its epimer, (±)-20-epiiboxyphylline (14b 15).