Total Synthesis and Structural Assignment of (-)-Fusaequisin A

(-)-Fusaequisin A is an irregularly assembled polyketide isolated from the ascomycete Fusarium equiseti. Fusaequisin A shares a carbon backbone with curvicollide C from the ascomycete Podospora curvicolla but its absolute configuration remained hitherto unsettled. Herein, we document the total synthesis of (-)-fusaequisin A and its 4-O-desmethyl derivative following a central-to-lateral building block strategy. Catalytic asymmetric Claisen rearrangement, Julia-Kocienski olefination and olefin cross-metathesis served as key C/C-connecting transformations. The constitution and absolute configuration of (-)-fusaequisin A was deduced and the original structural assignment was adjusted.

Automated summary

The total synthesis of (-)-Fusaequisin A was documented, using a central-to-lateral building block strategy. Key C/C-connecting transformations such as catalytic asymmetric Claisen rearrangement, Julia-Kocienski olefination, and olefin cross-metathesis were utilized. The constitution and absolute configuration of (-)-Fusaequisin A were deduced and the original structural assignment was adjusted.