A SIMPLE APPROACH TO THE SYNTHESIS OF FUROFURANS AND FUROPYRROLES USING 3-PHENACYLATED TETRAHYDRO-2-IMINO-3-FURANCARBONITRILES

作者：Maruoka Hiroshi^*; Okabe Fumi; Masumoto Eiichi; Fujioka Toshihiro; Yamagata Kenji

来源：Heterocycles, 2010, 80(1): 637-644.

DOI：10.3987/COM-09-S(S)48

• Furofuran
• Furopyrrole
• Phenacylation
• Cyclization
• Heterobicycle

A new and easy synthetic route to furo[2,3-b]furans 7a-d and furo[2,3-b]pyrroles 8a-d has been achieved by the C-phenacylation/cyclization reactions of 2-amino-4,5-dihydro-3-furancarbonitrile (5). Thermal treatment of the key intermediate 3-phenacylated tetrahydro-2-imino-3-furancarbonitriles 6a-d, which were prepared from compound 5 and phenacyl bromides, e.g. phenacyl bromide, 4-chlorophenacyl bromide, 4-methylphenacyl bromide and 4-methoxyphenacyl bromide, with acetic anhydride caused intramolecular cyclization to yield the corresponding furo[2,3-b]furans 7a-d. On the other hand, methanolic sodium methoxide-assisted cyclocondensation of compounds 6a-d gave the corresponding furo[2,3-b]pyrroles 8a-d.

• 出版日期2010-1-1