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: ¥ 4,320 (Yen only)
Period: This Article can be accessed for 7 days.

Paper | Regular issue | Vol 65, No. 6, 2005, pp.1321-1327
Published online, 24th March, 2005
DOI: 10.3987/COM-05-10359
Synthesis of Thienobenzofuranquinone Derivatives by Photoinduced and CAN-mediated 3+2-Type Cycloaddition Reactions

Kazuhiro Kobayashi,* Keiichi Yoneda, Kazutaka Hayashi, Osamu Morikawa, and Hisatoshi Konishi

*Department of Materials Science, Faculty of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan

Abstract

Photoinduced cycloaddition between ethyl 5-hydroxy-3-methyl-4,7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylate (1a) and alkenes is reported to give ethyl 7-methyl-4,8-dioxo-2,3,4,8-tetrahydrothieno[2,3-f]benzofuran-6-carboxylates (2). Cerium(IV) ammonium nitrate (CAN)-mediated cycloaddition of ethyl 5-hydroxy-4,7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylates (1) to alkenes or phenylacetylene, giving ethyl 4,8-dioxo-4,8-dihydrothieno[2,3-f]benzofuran-6-carboxylate (2 or 4) and ethyl 4,5-dioxo-4,5-dihydrothieno[3,2-g]benzofuran-7-carboxylate derivatives (3 or 5), is also reported.