Stereospecific Total Synthesis of the Indole Alkaloid Ervincidine. Establishment of the C‑6 Hydroxyl Stereochemistry

The
total synthesis of the indole alkaloid ervincidine (3) is reported. This research provides a general entry into C-6 hydroxy-substituted
indole alkaloids with either an α or a β configuration.
This study corrects the errors in Glasby’s book (Glasby, J. S. Encyclopedia of the Alkaloids; Plenum Press: New York, 1975) and Lounasmaa et al.’s review
(Lounasmaa, M.; Hanhinen, P.; Westersund, M. In The Alkaloids; Cordell, G. A., Ed.; Academic Press: San Diego, CA, 1999; Vol. 52, pp 103–195) as well as clarifies the work
of Yunusov et al. (Malikov, V. M.; Sharipov, M. R.; Yunusov, S. Yu. Khim. Prir. Soedin. 1972, 8, 760−761. Rakhimov, D. A.; Sharipov, M. R.; Aripov, Kh. N.; Malikov, V. M.; Shakirov, T. T.; Yunusov, S. Yu. Khim. Prir. Soedin. 1970, 6, 724–725). It establishes the correct absolute configuration
of the C-6 hydroxyl function in ervincidine. This serves as a structure
proof and corrects the misassigned structure reported in the literature.