The Cyclic Nitronate Route to Pharmaceutical Molecules: Synthesis of GSK’s Potent PDE4 Inhibitor as a Case Study
作者:Evgeny V. Pospelov、Ivan S. Golovanov、Sema L. Ioffe、Alexey Yu. Sukhorukov
DOI:10.3390/molecules25163613
日期:——
from a catechol-derived nitroalkene. The key intermediate (3-acyloxymethyl-substituted 1,2-oxazine) was prepared in a straightforward manner by tandem acylation/(3,3)-sigmatropic rearrangement of the corresponding 1,2-oxazine-N-oxide. The latter was assembled by a (4 + 2)-cycloaddition between the suitably substituted nitroalkene and vinyl ether. Facile acetal epimerization at the C-6 position in 1,2-oxazine
葛兰素史克的强效 PDE4 抑制剂的有效不对称合成是从邻苯二酚衍生的硝基烯烃中分八步完成的。关键中间体(3-酰氧基甲基取代的 1,2-恶嗪)通过相应的 1,2-恶嗪-N-氧化物的串联酰化/(3,3)-σ 重排以简单的方式制备。后者通过适当取代的硝基烯烃和乙烯基醚之间的 (4 + 2)-环加成组装而成。在用 NaBH3CN 在 AcOH 中还原的过程中观察到在 1,2-恶嗪环的 C-6 位置上容易缩醛差向异构化。密度泛函理论 (DFT) 计算表明差向异构化可能通过一个不寻常的三环 oxazolo(1,2)oxazinium 阳离子进行,该阳离子通过来自远处酰氧基和 1,2-oxazine 环的氮原子的双嵌合辅助形成。