Cylindricines C-G, Perhydropyrrolo[2,1-j]quinolin-7-one Alkaloids From the Ascidian Clavelina cylindrica

Abstract

Five novel perhydropyrrolo [2,1-j]quinolin-7-one alkaloids have been isolated from two different Tasmanian collections of the ascidian Clavelina cylindrica. The compounds, cylindricines C-G, are closely related in structure to cylindricine A which has been obtained previously from the same ascidian. Cylindricines F and G are thiocyanates, the first known from an ascidian . The identification of the new alkaloids was by ¹H n.m.r. and ¹³C n.m.r. spectroscopy, high-resolution e.i . mass spectrometry, and chemical interconversions.