P3 Towards the Synthesis of Martinella Alkaloids

P3 Towards the Synthesis of Martinella Alkaloids 

Marianne Bore Haarr0, Emil Lindbäck0 and Magne Sydnes0

0Department of Mathematics and Natural Science, University of Stavanger, Norway
Email: magne.o.sydnes@uis.no

Martinelline (1) and Martinellic acid (2) were in 1995 isolated from M. iquitosensis root extracts [2]. The isolated compounds, in particular Martinelline, were found to display bradykinin antagonistic activity. Martinelline also possessed antimicrobial properties and high binding affinity to
α1-adrenergic and muscarinic receptors [1,2]. Herein we present our first-generation catalytic enantioselective synthesis of the partially reduced quinoline core structure of the Martinella alkaloids in 75% ee [3]. In our second-generation approach towards the Martinella core structure and subsequently towards alkaloids 1 and 2, absolute stereochemistry is installed using Sharpless asymmetric epoxidation [4], followed by aminolysis of the epoxide.

1. Gentry; Cook, J. Ethnopharmacol. 1984, 11, 337.
2. Witherup, et al. J. Am. Chem. Soc. 1995, 117, 6682.
3. Lindbäck; Sydnes, ChemistrySelect 2016, 1, 1837.
4. Caron; Sharpless, J. Org. Chem. 1985, 50, 1557.