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Communication | Special issue | Vol 77, No. 1, 2009, pp.241-247
Published online, 1st September, 2008
DOI: 10.3987/COM-08-S(F)52
Facile Construction of Furan-fused Methano[11]annulenone Skeleton by Successive Aldol Condensations from 3,4-Furan-dicarbaldehydes

Yanmei Zhang, Nobuhiko Takezawa, oshikazu Horino, Ayumi Takai, Yasutomo Tsuji, Ryuta Mityatake, Mitsunori Oda,* Shigeyasu Kuroda*

*Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan

Abstract

Aldol condensation of furan-3,4-dicarbaldehyde with pentanedial in acetic acid gave 6H-cyclohepta[c]furan-5,7-dicarbaldehyde in a good yield. Then, successive condensation of 6H-cyclohepta[c]furan-5,7-dicarbaldehyde with dimethyl 1,3-acetonedicarboxylate under azeotropic conditions gave a diester derivative of furan-fused methano[11]annulenone also in a good yield. The hydrolysis of the diester groups and subsequent decarboxylation provided a non-substituted furan-fused methano[11]annulenone. A similar sequence starting from 2,5-dimethylfuran-3,4-dicarbaldehyde gave its dimethyl derivative. Cycloaddition and protonation of these furan-fused methano[11]annulenones were also studied.