A practical synthetic protocol for diverse spiro and fused furan frameworks was developed by isocyanide‐based three‐component reactions. The three‐component reaction of alkyl isocyanides, dialkyl but‐2‐ynedioates, and 3‐( o ‐hydroxyphenacylidene)oxindoles or 2‐(indol‐3‐yl)indene‐1,3‐diones afforded special spirobenzofuran‐3,2′‐furans and indeno2,1‐ b oxeto2,3‐ c furans in good yields and with high diastereoselectivity. The single crystal structure determination showed that the unique polycyclic compounds with spiro and fused furan frameworks were efficiently formed.
Zhang et al. (Sat,) studied this question.