New strategy for the synthesis of proaporphine and homoproaporphine-type alkaloids from a common intermediate
作者:Philip Magnus、Kyle D. Marks、Alan Meis
DOI:10.1016/j.tet.2015.04.023
日期:2015.6
coupled with the boronic anhydride 15 using standard Suzuki reaction conditions to give 16 (91%). The aldehyde 16 was exposed to classical nitro-aldol reaction conditions to give 17 (88%), and conjugatively reduced with DIBAL-H to give 18 (91%). Protection of the amine 18 as its N-carbamate derivative 19, followed by condensation with glycol aldehyde dimer under acidic reaction conditions gave 20 (78%)
从3-溴-4,5-二甲氧基苯甲醛14开始,使用标准的Suzuki反应条件将其与硼酸酐15偶联,得到16(91%)。将醛16暴露于经典的硝基-醛醇缩合反应条件下得到17(88%),并用DIBAL-H共轭还原得到18(91%)。保护胺18作为其N-氨基甲酸酯衍生物19,然后在酸性反应条件下与二醇醛二聚体缩合,得到20(78%)。随后将20转化为其甲磺酸酯衍生物21,并在非质子反应条件下暴露于CsF,得到22(81%)。通过8个步骤使22的脱保护给出(±)-斯蒂芬琳10,以29%的总收率获得。相似的反应条件序列将胺18转化为-NTs保护的高原卟啉加合物28。