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:

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

Communication | Regular issue | Vol 63, No. 8, 2004, pp.1765-1770
Published online, 6th July, 2004
DOI: 10.3987/COM-04-10138
Synthesis of 5-Methylindole-4,7-quinone through a New Construction of the Functionalized Indole Ring Based on the Allene-mediated Electrocyclic Reaction Involving the Pyrrole [b]-Bond

Maho Hirayama, Tominari Choshi, Teppei Kumemura, Shigeo Tohyama, Junko Nobuhiro, and Satoshi Hibino*

*Graduate School of Pharmacy and Pharmaceutical Sciences, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Fukuyama, Hiroshima 729-0292, Japan


A new synthesis of an indole ring based on an electrocyclic reaction of a 2-alkenyl-3-allenylpyrrole intermediate generating from 2-ethenyl-3-propargylpyrrole was established. A synthesis of 5-methylindole-4,7-quinone (1) was completed in seven steps from the 4-oxygenated 5-methylindole (13a). It was demonstrated that the structure of natural product (1), isolated from Dropella fragum, is not at least 5-methylindole-4,7-quinone (1).