Total Synthesis of (-)-Ulapualide A: The Danger of Overdependence on NMR Spectroscopy in Assignment of Stereochemistry

摘要

Ulapualide A (1) and its relatives,for example,mycalolide A (2),are an intriguing family of trisoxazole-based macrolides which have been isolated from marine nudibranchs (sea slugs) and sponges.The metabolites show antifungal activity and ichthyotoxic properties,and they also show activity against L1210 leukemia cells.Although the ulapualides have been known since 1986,their complete stereochemistries were not defined until quite recently following degradation and synthetic studies,and,in particular,X-ray studies of some of their complexes with the protein actin.