Spirodionic Acid, a Novel Metabolite fromStreptomyces sp., Part 2: Total Synthesis through a Twofold Michael Addition as a Selective Spiroannelation Strategy
作者:Jürgen Siewert、Adriana Textor、Stephanie Grond、Paultheo von Zezschwitz
DOI:10.1002/chem.200601688
日期:2007.9.7
at C4 and C5 were prepared. The first access involved the synthesis of 3-ethenyl-2-formylcyclopentanone (8) using a three-component coupling process. A sequence of Michael addition to penten-3-one (7) and intramolecular aldol condensation then led to the highlyselective formation of the 4S*,5S*-configured spirocycle 5. In contrast, a selective spiroannelation of a cyclohexenone ring was accomplished