作者:Daniel Kracht、Susumu Saito、Bernhard Wünsch
DOI:10.1071/ch09206
日期:——
six-step synthesis of the benzyl and allyl substituted bicyclic ketones 3a and 3b, which represent interesting building blocks for the synthesis of conformationally restricted receptor ligands. The key steps of the synthesis are the regioselective addition of ethyl acrylate to the piperazine 8, the sodium hexamethyldisilazide-induced Dieckmann cyclization of the diesters 10, and the decarboxylation of the
1,4-二氮杂双环[3.3.1]壬烷(氮杂吗啡)代表构象受限的哌嗪衍生物。在这里,我们报告了六步合成苄基和烯丙基取代的双环酮3a和3b的过程,它们代表了构象受限受体配体合成的有趣结构单元。合成的关键步骤是将丙烯酸乙酯区域选择性地添加到哌嗪8中,六甲基二硅叠氮化钠诱导的二酯10的Dieckmann环化,以及用稀HCl使烯醇酯11脱羧。仅当苄基(10a)或烯丙基部分(10b)时,完整序列才成功由于甲苯磺酰基衍生物10f不能给出狄克曼环化产物,并且酰基衍生物11c和11d的脱羧作用失败,所以将其连接到N-1上。