Synthesis of Alocasin A.

Herein is reported a synthesis of alocasin A (1), an alkaloid component of Alocasia macrorrhiza, a herbaceous plant used in folk medicine throughout southern Asia. A double Suzuki-Miyaura cross-coupling reaction between a 3-borylindole and 2,5-dibromopyrazine was used to assemble the heteroaromatic framework of the natural product. Removal of the protecting groups gave a synthetic sample of 1, the spectroscopic data of which matched those in the isolation report of this compound.