Enantioselective synthesis of (−)-meroquinene through tandem Michael reaction methodology.
作者:Achille Barco、Simonetta Benetti、Carmela De Risi、Gian P. Pollini、Romeo Romagnoli、Giampiero Spalluto、Vinicio Zanirato
DOI:10.1016/s0040-4020(01)86974-x
日期:1994.2
chromatography after transformation of the nitrogen protective benzyl group into the corresponding carbamates 14 and 15. Both compounds, after elaboration of the chain geminal to the nitro group into a vinyl appendage. underwent regio- and stereo-selective removal of the nitro group by palladium-catalyzed displacement with hydride generated by formate to give the precursor 19, easily converted by treatment
基于(L )-薄荷基N-苄基-5-氨基-2E-戊烯酸酯3和1-乙酰氧基-4-甲氧基甲基氧基之间的分子间和分子内迈克尔顺序反应的非天然(-)-间苯二酚1的对映选择性合成方法描述了充当2-硝基-1,3-丁二烯4的替代物的-2-硝基丁烷10b。杂环化过程导致形成哌啶环系统12,该哌啶环系统是在C-3和C-4处新创建的手性中心以非分离的非对映异构体80:20混合物的形式获得的,在转化后,可通过柱色谱法轻松分离氮保护苄基变成相应的氨基甲酸酯14和15。在将与硝基成对的双链精加工成乙烯基附件后,将这两种化合物合成。通过用甲酸生成的氢化物通过钯催化的置换,进行区域和立体选择性除去硝基,得到前体19,其易于通过盐酸处理转化为1,以盐酸盐的形式分离。