Concise Formal Total Synthesis of Hybocarpone and Related Naturally Occurring Naphthazarins
作者:Christina L. L. Chai、John A. Elix、Felicity K. E. Moore
DOI:10.1021/jo0519561
日期:2006.2.1
4-naphthoquinone (aureoquinone) and 3-ethyl-2,5,7,8-tetrahydroxy-1,4-naphthoquinone, respectively. An alternative selective synthetic route to 3-ethyl-2-hydroxy-5,7,8-trimethoxy-6-methyl-1,4-naphthoquinone was also developed utilizing an intramolecular Claisen condensation of methyl 2-butyryl-3,5,6-trimethoxy-4-methylphenylacetate with concomitant in situ aerial oxidation.
通过开发合成前体3-乙基-2-羟基-5,7,8-三甲氧基-6-甲基-1,4-萘醌的途径,已完成了对细胞毒性的比那撒林衍生物羟卡巴酮的简明正式全合成。在Rapoport条件下氧化3-乙基1,2,4,5,7,8-六甲氧基-6-甲基萘得到3-乙基-2-羟基-5,7,8-三甲氧基-6-甲基-1,碱性水解后,4-萘醌的产率中等。另外,用三溴化硼处理3-乙基-1,2,4,5,7,8-六甲氧基-6-甲基萘提供了与天然存在的萘他林硼喹酮的接触的途径。3,6-二甲基-1,2,4,5,7,8-六甲氧基萘和3-乙基-1,2,4,5,7,8-六甲氧基萘的类似氧化脱甲基作用导致合成2,5 ,7,8-四羟基-3,6-二甲基-1,4-萘醌(aureoquinone)和3-ethyl-2,5,7,8-四羟基-1,4-萘醌。还开发了一种利用3-甲基-2-丁酰基-3,5,6的分子内克莱森缩合法合成3-乙基-2-羟基-5,7,8-三甲氧基-6-甲基-1