123958-37-2Relevant articles and documents
Furan Derivatives. Part 10. Synthesis of Cycloheptabenzofuran
Horaguchi, Takaaki,Hasegawa, Eietsu,Shimizu, Takahachi,Tanemura, Kiyoshi,Suzuki, Tsuneo
, p. 365 - 369 (2007/10/02)
Cycloheptabenzofuran 2 was synthesized by heating (5-oxo-5H-benzocyclohepten-4-yloxy)acetic acid 16 with sodium acetate in acetic anhydride or by photocyclization of 16 in acetonitrile.Several reactions of cycloheptabenzofuran 2 were examined.Protonation of 2 with trifluoroacetic acid occurred at the 2-position to give a tropylium ion 17.Catalytic hydrogenation of 2 with palladium on charcoal proceeded smoothly to give tetrahydrocycloheptabenzofuran 18.The Diels-Alder reaction of 2 with tetracyanoethylene produced an adduct 19.Formylation of 2 with phosphorus oxychloride and dimethylformamide occurred easily at the 2-position to afford compound 20.Cycloheptabenzofuran 2 has both properties of heptafulvene and benzofuran.