Diels−Alder Reactions of 5-Alkyl-1,3-cyclopentadienes
作者:Johnathon E. Letourneau、Mark A. Wellman、D. Jean Burnell
DOI:10.1021/jo9707949
日期:1997.10.1
preference for syn addition with less encumbered dienophiles. This may indicate a conformational difference in its syn transition state relative to the transition states for addition syn to methyl, ethyl, or n-butyl substituents (dienes 1, 4, and 5). Dienophiles are more reluctant to add syn to the larger C-5 group with 1,2,3,4,5-pentamethyl-1,3-cyclopentadiene (2) and derivatives (3, and 7) and conformational