Pharmaceutical Sciences and Health Technologies I.
Orthoscuticellines A and B are newly isolated natural β-carboline alkaloids from the moss animal Orthoscuticella ventricosa. Herein, we report the first targeted total synthesis of orthoscuticelline B and an analogous synthetic method for the preparation of dihydro derivate of orthoscuticelline A. The new synthetic approach is based on commercially available and inexpensive reagents leading to a practical synthesis of the target molecules. The reaction sequence consisting of a T3P®-catalyzed amide formation followed by a Bischler–Napieralski cyclisation and a DDQ-assisted dehydrogenation step ensures a practical access to orthoscuticelline B in three steps with 58% overall yield.
This work was prepared in the framework of 2020-1.1.2-PIACI-KFI-2020-00039 project with the support of the Ministry of Culture and Innovation from National Research Development and Innovation Fund.