Synthesis of New 3-(-2-Alkenyl)-2-hydroxy-5-methoxy-<i>p</i>-benzoquinones via Claisen Rearrangement of Original 5-Methoxy-4-(2-propenyloxy)-<i>o</i>-benzoquinones
作者:Olivia Reinaud、Patrice Capdevielle、Michel Maumy
DOI:10.1055/s-1988-27547
日期:——
The Claisen rearrangement is extended to compounds containing the benzoquinone moiety, obtained by regioselective nucleophilic substitution on 4-(p-methoxyphenoxy)-5-methoxy-o-benzoquinone (1). In the most general case, 5-methoxy-4-(2-propenyloxy)-o-benzoquinones 3 rearrange quantitatively into (E)-3-(2-alkenyl-2-hydroxy-5-methoxy-p-benzoquinones 4. Furfuryl or (2-thienyl)methyl ethers isomerize to 3-(2-methyl-3-furyl)- and 3-(2-methyl-3-thienyl)-2-hydroxy-5-methoxy-p-benzoquinones. This new synthetic method provides an efficient route to new hydroxybenzoquinones closely related to natural compounds. Thus, dihydroardisiaquinone A is synthesized in 5 steps from p-methoxyphenol.
克莱森重排扩展到含有苯醌部分的化合物,该化合物通过 4-(对甲氧基苯氧基)-5-甲氧基-邻苯醌 (1) 上的区域选择性亲核取代获得。在最常见的情况下,5-甲氧基-4-(2-丙烯氧基)-邻苯醌 3 定量重排成 (E)-3-(2-烯基-2-羟基-5-甲氧基-对苯醌 4)。或(2-噻吩基)甲基醚异构化为3-(2-甲基-3-呋喃基)-和3-(2-甲基-3-噻吩基)-2-羟基-5-甲氧基-对苯醌。该方法为与天然化合物密切相关的新羟基苯醌提供了一条有效的途径,因此,二氢紫心醌A是由对甲氧基苯酚通过5步合成的。