The collective and efficient asymmetric total syntheses of five β-carboline-type monoterpenoid indole alkaloid glycosides were achieved in fewer than thirteen steps. A Pictet–Spengler reaction with α-cyanotryptamine followed by the removal of the cyano group and autoxidation (aromatization) efficiently constructed the β-carboline motif. In addition, bioinspired reactions were developed to provide different alkaloid skeletons.
Key words
bioinspired reaction - monoterpenoid indole alkaloid - β-carboline - decyanation - Pictet–Spengler reaction