Total synthesis of 7-deoxypancratistatin-1-carboxaldehyde and carboxylic acid via solvent-free intramolecular aziridine opening: phenanthrene to phenanthridone cyclization strategy.

Solid-state silica-gel-catalyzed opening of aziridine 6 provided phenanthrene 7, whose oxidative cleavage, recyclization, and further elaboration furnished the C-1 aldehyde and carboxylic acid derivatives of 7-deoxypancratistatin for potential analogue synthesis.