4H,6H-thieno[3,4-c]furan 5,5-dioxide 1 was readily converted to the 4-alkylated compounds 2 and the appropriate compounds 2 were submitted to intramolecular DielsâAlder reactions to afford fused furans 8a and b in good yields.
4H,6H-thieno[3,4-c]furan 5,5-二氧化物 1 容易转化为 4-烷基化合物 2,并将适当的化合物 2 进行分子内 Diels–Alder 反应,得到良产率的融合
呋喃 8a 和 8b。