A practical synthesis of the C1-C14 polyene unit 5 in ansatrienin A (mycotrien I), 1a, and other ansamycin antibiotics is described which involves elaboration of the chiral unsaturated aldehyde 6 and phosphonate 7, followed by coupling of the building blocks by Horner-Emmons-olefination and Duthaler's aldolation. The synthesis of 6 successfully applies two consecutive Evans-aldol reactions for constructing the carbon backbone.
描述了安沙三宁 A (mycotrien I)、1a 和其他安沙霉素抗生素中 C1-C14 多烯单元 5 的实际合成,其中涉及手性不饱和醛 6 和
膦酸酯 7 的精制,然后通过 Horner- 偶联结构单元。 Emmons 烯化和 Duthaler 醛醇化。 6的合成成功地应用了两个连续的埃文斯-羟醛反应来构建碳主链。