Synthetic Studies on<i>d</i>-Biotin, Part 6:An Expeditious and Enantiocontrolled Approach to the Total Synthesis of<i>d</i>-Biotin via a Polymer-Supported Chiral Oxazaborolidine-Catalyzed Reduction of<i>meso-</i>Cyclic Imide Strategy
作者:Fen-Er Chen、Jian-Li Yuan、Hui-Fang Dai、Yun-Yan Kuang、Yong Chu
DOI:10.1055/s-2003-41051
日期:——
3-dibenzyl-2-imidazolidone-4,5-dicarboxylic acid (5) was accomplished in 48% overall yield. The key reactions in the sequence involve thecatalytic enantioselective reduction of meso-cyclic imide 6 using polymer-supported chiral oxazoborolidine, derived from (S)-α,α-diphenylprolinol and polymer-bound sulfonyl chloride, and the installation of the C 5 side chain at C4 in the thiolactone 9 via a Ni/C-catalyzed
从已知的 cis-1,3-dibenzyl-2-imidazolidone-4,5-dicarboxy 酸 (5) 高效且高度对映选择性地合成 d-生物素以 48% 的总产率完成。该序列中的关键反应涉及使用聚合物负载的手性恶唑硼烷催化对映选择性还原中间环酰亚胺 6,该反应衍生自 (S)-α,α-二苯基脯氨醇和聚合物结合的磺酰氯,以及 C 5 侧链的安装通过 Ni/C 催化的 Fukuyama 偶联反应在硫代内酯 9 中的 C4 处。