A new approach to fused furan ring systems and benzofurans: intramolecular cyclization reactions of unsaturated acyloxy sulfone derivatives

✍ Scribed by Yuan Liu; Hollie K. Jacobs; Aravamudan S. Gopalan

• Book ID: 104099118
• Publisher: Elsevier Science
• Year: 2011
• Tongue: French
• Weight: 726 KB
• Volume: 52
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2011.03.120

✦ Synopsis

Unsaturated acyloxy sulfones 3 undergo intramolecular cyclization upon deprotonation with LHMDS in THF. Dehydration and double bond isomerization of the products upon exposure to acid, gave the fused ring furans, 4, in good yields. This strategy could be readily adapted to prepare substituted benzofurans 12 from the cyclization reactions of acyloxy sulfones 11 prepared from phenols. Finally, this approach could be successfully modified to access dihydropyrans and benzopyrans.