Synthesis and reactions of some new substituted spirofurochromanone derivatives

✍ Scribed by El-Sayed I. El-Desoky; Mahmoud A. Hammad; Nabil Grant; Emad M. El-Telbany; Abdel Rahman H. Abdel-Rahman

• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 363 KB
• Volume: 53
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(97)10032-1

✦ Synopsis

Condensation of different cyclic ketones with visnaginone la and khellinone lb afforded spirofurochromanone derivatives 2a-f. Compounds 2a and 2b were readily demethylated to give the compounds 3a and 3b. Nitration of 2b and 2e gave the nitrofurochromonone and quinone derivatives 4 and 5 respectively. The chroman-4-ol derivatives 6a and 6b were obtained from reduction of 2b and 2e which were directly dehydrated to give compounds 7a and 7b respectively. Also, amide 6c was prepared which failed to provide 6d on acid hydrolysis. Bromination of the chromane 7a gave the corresponding 9-bromo derivative 7c and failed to give compound 8. Treatment of 2b with bIBS afforded the corresponding 2,9-dibromo derivative 10. The chromanones 2b and 2e were reacted with hydroxylamiae, phenyl hydrazine, aniline and paraformaldehyde to give the products lla-e and 12a,b