Abstract The final step in the biosynthesis of the natural product schischkiniin is proposed to be a photochemically driven [2+ 2]-cycloaddition between two dihydropyrazinone units tethered to a 1, 1′-bisindole. Herein, we describe the extensive efforts aimed at synthesizing the cycloaddition precursor 2, which has been obtained as its di-Boc protected derivative 30. Two bidirectional approaches were examined, both starting with the ...
