Ring Expansion and Ring Contraction Observed in Isopropenyldihydrofuran Derivatives
作者:Seiji Yamaguchi、Yoshihiko Sugioka、Yuzoh Kitagawa、Yoshinori Matsumoto、Hajime Yokoyama、Yoshiro Hirai
DOI:10.1246/bcsj.70.2777
日期:1997.11
5-dihydrofuran-2,3-dicarboxylic acid caused a new ring expansion to give 4,7-dihydro-6-methyloxepin-2,3-dicarboxylic anhydride (2b). An aminolysis of 2b with benzylamine gave a mixture of two isomeric carboxamides, N-benzyl-4,7-dihydro-6-methyloxepin-2-carboxamide and trans-1-(benzyloxamoyl)-2-isopropenylcyclopropane. Also, the ring expansion and ring contraction are discussed.
5-isopropenyl-4,5-dihydrofuran-2,3-二羧酸中的分子内酸酐形成导致新的环扩张,得到 4,7-dihydro-6-methyloxepin-2,3-二羧酸酐 (2b)。2b 与苄胺的氨解得到两种异构羧酰胺的混合物,N-benzyl-4,7-dihydro-6-methyloxepin-2-carboxamide 和 trans-1-(benzyloxamoyl)-2-isopropenylcyclopropane。此外,还讨论了环膨胀和环收缩。