Synthesis of trihydroxylated pyrrolizidine and indolizidine alkaloids based on SmI2-induced reductive coupling of chiral nitrones with methyl acrylate
作者:Juraj Rehák、Lubor Fišera、Jozef Kožíšek、Lenka Bellovičová
DOI:10.1016/j.tet.2011.05.129
日期:2011.8
Synthesis of trihydroxylated pyrrolizidines, the enantiomer of 2-epihyacinthacine A2 and indolizidine analogues of the natural alkaloids is reported. The key step of these syntheses is the stereoselective samarium diodide-induced coupling of the chiral nitrone prepared from d-ribose with methyl acrylate. The nitrone derived from d-ribose possessing C2/C3 syn configuration reacted with methyl acrylate
据报道,合成了三羟基化的吡咯嗪核苷,2-表庚氨酸A 2的对映异构体和天然生物碱的吲哚并嗪类似物。这些合成的关键步骤是立体选择性二碘化mar诱导的由d-核糖与丙烯酸甲酯制备的手性硝酮的偶联。在二碘化sa存在下,具有C2 / C3顺式构型的d-核糖衍生的硝酮与丙烯酸甲酯反应,具有极好的收率和非对映选择性,仅检测到抗-非对映异构体。