Oxidative demethylation of 2-(α-hydroxyalkyl- and α-oxoalkyl)-1,4,5,8-tetramethoxynaphthalene with (NH4)2Ce(NO3)6 gave two isomeric dimethoxynaphthoquinones: 2-substituted and 6-substituted 5,8-dimethoxy-1,4-naphthoquinones. Further demethylations of the former isomers to the corresponding dihydroxynaphthoquinones required an AgO–40%HNO3 reagent, while the latter isomers needed AlCl3 as the demethylation
2-(α-羟烷基-和α-氧代烷基)-1,4,5,8-四甲氧基
萘与 (NH4)2Ce(
NO3)6 的氧化脱甲基得到两种异构二甲氧基
萘醌:2-取代和 6-取代的 5,8-二甲氧基-
1,4-萘醌。前者异构体进一步去甲基化为相应的二羟基
萘醌需要 AgO–40%H 试剂,而后者异构体需要
AlCl3 作为去甲基化试剂。给出了关于这些用 (NH4)2Ce( )6 进行氧化去甲基化的机制的一些评论。