Synthesis of the unique angular tricyclic chromone structure proposed for aspergillitine, and its relationship with alkaloid TMC-120B
作者:Sebastián O. Simonetti、Enrique L. Larghi、Andrea B. J. Bracca、Teodoro S. Kaufman
DOI:10.1039/c2ob25067e
日期:——
The synthesis of the tricyclic angular chromone structure originally assigned to aspergillitine is reported. The synthesis was achieved in 11 steps and 15% overall yield from 2,4-dihydroxypropiophenone, through the intermediacy of 2,3-dimethyl-7-hydroxychromen-4-one. Construction of the nitrogen-bearing heterocyclic ring entailed a Stille cross-coupling reaction with n-Bu3SnCH2CHCH2, followed by double bond isomerization, oximation of the chromone carbonyl, and a final microwave-assisted electrocyclization of the thus formed 6π-electron aza-triene system.
报道了最初分配给阿斯彭吉林的三环角状香豆素结构的合成。这一合成过程经过11步,从2,4-二羟基丙酮开始,整体收率为15%。合成过程中的中间体为2,3-二甲基-7-羟基香烯-4-酮。氮含有杂环的建设包括与n-Bu3SnCH2CHCH2的斯蒂尔交叉偶联反应,随后进行双键异构化、香豆素羰基的氧肟化,最后通过微波辅助电环化反应形成6π-电子的氮杂三烯系统。