e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Journal of natural products
Progress in the synthesis of canthine alkaloids and ring-truncated congeners
HDH Showalter
Index: Baradarani, M. Mehdi; Dalton, Lesley; Heatley, Frank; Cohylakis, Demetrios; Joule, John A. Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1985 , p. 1503 - 1508