Short, Chemoenzymatic Access to Cyctetryptomycin A and B

A concise and chemoenzymatic synthesis of cyctetryptomycin A and B (1-2) using a Zr-catalyst and CttpC is reported. The recent discovery of cyctetryptomycin A and B (1-2) and their intriguing neuroprotective activities necessitated scalable synthesis to facilitate structure-activ-ity relationship studies. However, the synthesis of cyctetryptomycin A and B (1-2) solely by chemical reactions has proven to be impractical. Therefore, a novel approach using a short and chemoenzymatic strategy was developed to prepare cyctetryptomycin A and B (1-2) via Zr-catalyzed construction of two consecutive quaternary chiral carbons and CttpC-catalyzed direct oxidative coupling of the tryptophan moiety.