A new synthetic route to 2-substituted naphtho[2,3-b]furan-4,9-dione2-Substituted Naphtho[2,3-b]furan-4,9-dione

✍ Scribed by Jyunichi Koyanagi; Katsumi Yamamoto; Kouji Nakayama; Akira Tanaka

• Publisher: Journal of Heterocyclic Chemistry
• Year: 1997
• Tongue: English
• Weight: 476 KB
• Volume: 34
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570340209

✦ Synopsis

Abstract

4,9‐Dimethoxynaphtho[2,3‐b]furan 9 was obtained in 91% yield via the reductive methylation of naphtho[2,3‐b]furan‐4,9‐dione 2. After treatment of 9 with butyllithium, the mixture was allowed to react with N,N‐dimethylacetamide, followed by oxidization with cerium(IV) diammonium nitrate to give 2‐acetylnaphtho[2,3‐b]furan‐4,9‐dione 1. 2‐Formylnaphtho[2,3‐b]furan‐4,9‐dione 13 and 2‐trimethylsilyl‐naphtho[2,3‐b]furan‐4,9‐dione 14 were also obtained from 9 by a similar method. The halodesilylations of 14 easily gave 2‐iodonaphtho[2,3‐b]furan‐4,9‐dione 16, 2‐bromonaphtho[2,3‐b]furan‐4,9‐dione 17, and 2‐chloronaphtho[2,3‐b]furan‐4,9‐dione 18 in 82%, and 93% and 83% yield, respectively. Furthermore, the nitrodesilylation of 14 gave 2‐nitronaphtho[2,3‐b]furan‐4,9‐dione 3 in 77% yield.