New Synthetic Approach to Naphtho[1,2-b]furan and 4′-Oxo-Substituted Spiro[cyclopropane-1,1′(4′H)-naphthalene] Derivatives

✍ Scribed by Axelle Arrault; Jean-Yves Mérour; Jean-Michel Léger; Christian Jarry; Gérald Guillaumet

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: German
• Weight: 178 KB
• Volume: 84
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/1522-2675(20010815)84:8<2198::aid-hlca2198>3.0.co;2-j

✦ Synopsis

A one-step synthesis of ethyl 2,3-dihydronaphtho[1,2-b]furan-2-carboxylate and/or ethyl 4'-oxospiro[cyclopropane-1,1'(4'H)-naphthalene]-2'-carboxylate derivatives 2 and 3, respectively, from substituted naphthalen-1-ols and ethyl 2,3-dibromopropanoate is described (Scheme 1). Compounds 2 were easily aromatized (Scheme 2). In the same way, 3,4-dibromobutan-2-one afforded the corresponding 1-(2,3-dihydronaphtho[1,2-b]furan-2-yl)ethanone and/or spiro derivatives 8 and 9, respectively (Scheme 6). A mechanism for the formation of the dihydronaphtho[1,2-b]furan ring and of the spiro compounds 3 is proposed (Schemes 3 and 4). The structures of spiro compounds 3a and 3f were established by X-ray structural analysis. The reactivity of compound 3a was also briefly examined (Scheme 9). Scheme 4