Total Synthesis of Bastadins 2, 3, and 6

Abstract

A chemoenzymatic strategy has been developed for the synthesis of bastadins 2, 3, and 6. The requisite dimeric dityrosine and isodityrosine building blocks were successfully prepared by oxidative C−C and C−O phenolic coupling of mono- and dihalogenated derivatives of tyrosine and tyramine using horseradish and soybean peroxidases. By carefully controlling the experimental parameters, the requisite synthons may now be prepared in synthetically useful yields without the exhaustive protection and deprotection of the sensitive functional groups.