Potentially Biomimetic Total Synthesis and Relative Stereochemical Assignment of (±)‐Gracilamine

Gracil(e): The total synthesis of gracilamine features a potentially biomimetic intramolecular [3+2] cycloaddition to assemble its two fused five-membered rings and a debenzylation/ring-opening reaction to obtain the aldehyde intermediate (see scheme). The success of this synthesis provides a circumstantial evidence that supports the biosynthesis pathway of gracilamine proposed previously.