The competitive ortho directing (cod) influence of a 1-methoxy group and a 4-methyl group and a 4-methyl was studied in the Diels-Alder addition of 1-methoxy-1, 3-pentadiene (1) to 2, 6-dimethylbenzoquinone (2). It was found that the cod influence of a terminally located methoxy is stronger than the effect of a terminal methyl group in the diene since only adduct 3 could be isolated. The influence of non-terminal substituents compared to terminal ...
