McErlean Christopher S P, Moody Christopher J
School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom.
J Org Chem. 2007 Dec 21;72(26):10298-301. doi: 10.1021/jo702101w. Epub 2007 Nov 14.
The first synthesis of the unusual nitrogen-containing 3-alkyl-1,4-benzoquinone, N-(3-carboxylpropyl)-5-amino-2-hydroxy-3-tridecyl-1,4-benzoquinone, isolated from Embelia ribes, is reported. The key steps are a microwave-assisted combined Mitsunobu reaction-Claisen rearrangement to introduce the alkyl side chain into 2,5-dimethoxyphenol, followed by alkene reduction, oxidation to the quinone, and sequential displacement of the methoxy groups with hydroxide and GABA tert-butyl ester. Two other naturally occurring benzoquinones, O-methylrapanone and rapanone, were also prepared en route.
报道了从紫金牛属植物中分离得到的一种不寻常的含氮3-烷基-1,4-苯醌，即N-(3-羧丙基)-5-氨基-2-羟基-3-十三烷基-1,4-苯醌的首次合成。关键步骤包括微波辅助的Mitsunobu反应与克莱森重排相结合，将烷基侧链引入2,5-二甲氧基苯酚中，随后进行烯烃还原、氧化为醌，以及用氢氧化物和γ-氨基丁酸叔丁酯依次取代甲氧基。在此过程中还制备了另外两种天然存在的苯醌，即O-甲基拉帕酮和拉帕酮。
