(2, 5)-Ene cyclization catalyzed by mesoporous solid acids: Isotope labeling study and ab initio calculation for continuum from concerted to stepwise ene mechanism
K Mikami, H Ohmura, M Yamanaka
文献索引：Mikami, Koichi; Ohmura, Hirofumi; Yamanaka, Masahiro Journal of Organic Chemistry, 2003 , vol. 68, # 3 p. 1081 - 1088
(2, 5)-Ene reactions catalyzed by mesoporous solid acids are reported from the mechanistic point of view. The continuum (2, 5)-ene mechanism from the concerted to the cationic cyclization followed by 1, 2-hydride shift is evaluated. The solid-acid-catalyzed cyclization of the oxonium ion intermediate 4 derived from cyclic allylic lactol ether 3 bearing allylic hydroxy group affords the (2, 5)-ene product as the enol form, eventually tautomerizing to ...
