**5. Conclusions**

Pyrrole alkaloids, a very rich family of secondary metabolites widespread among marine organisms, have fascinated the chemical community for many decades. Their large structural variety not only endows them with unique biological activities but also prompts questions concerning the biochemistry of marine life which still require a thorough examination. On the other hand, the seemingly endless number of architectural complex pyrrole alkaloids discovered so far has also led to a considerable number of structural revisions, and the literature is riddled with unknown stereochemistries and inconsistencies in their naming. Synthetic chemists are animated to find new solutions concerning the total syntheses of marine pyrrole alkaloids, thereby providing a larger availability of these compounds which is crucial for the development of derivatives with improved biological activities. New and improved analytical techniques are needed to allow the unambiguous elucidation of relative and absolute configurations of the often-minute quantities of marine natural products available from their producers.

**Author Contributions:** Conceptualization, T.O., K.S. and L.G.; writing—original draft preparation, K.S. and L.G.; writing—review and editing, T.O., K.S. and L.G.; visualization, K.S. and L.G.; supervision, T.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
