Indole as a tool in synthesis. Indolenine approach to 4,5-epoxy-10-normorphinans
作者:Janos Sapi、Seloua Dridi、Jacqueline Laronze、Françoise Sigaut、Dominique Patigny、Jean-Yves Laronze、Jean Lévy、Loïc Toupet
DOI:10.1016/0040-4020(96)00378-x
日期:1996.6
B-ring were synthesized using the “nitrous acid deamination” of indolenines as the key step. Thus, indolenines 13 and 15 were prepared by Fischer synthesis from the corresponding bicyclic ketolactams 6 and 12, respectively, and further transformed into the related hexahydrodibenzofurans. Ketolactam 6 was obtained from 3-nitromethylcyclohexanone using classical chemistry, whereas 12 was built up by fragmentation
以吲哚烯酮的“亚硝酸脱氨基”为关键步骤合成了特征在于缺乏B环的吗啡骨架的4,5-环氧-10去甲吗啡喃2a和2b。因此,通过费歇尔合成法分别从相应的双环酮内酰胺6和12制备吲哚啉13和15,并将其进一步转化为相关的六氢二苯并呋喃。酮内酰胺6是使用传统化学方法从3-硝基甲基环己酮中获得的,而12通过使全氢pin庚酮断裂,然后进行分子内Diels-Alder环化作用来形成“环糊精”。虽然该过程导致了不自然的环连接(2b),但通过碱催化4,5-环氧17-甲基-9-氧代-10-nor-14α-吗啡喃21的差向异构化获得了自然构型(2a)。