This paper describes a convenient approach to the 7-aza-des-A-steroid (6,6a,7,8,9,9a-hexahydro-5H-cyclopenta[h]quinoline) scaffold starting from Grundmann's ketone using two different pyridine annulation protocols. The biological evaluation of the pyridine and pyridinium products revealed that these compounds unexpectedly do not interfere with ergosterol and cholesterol biosynthesis. The pyridinium compound 6 showed significant antimicrobial and cytotoxic activities which are most likely due to its detergent-like structure.
Keywords: Annulation; Antimicrobial activity; Azasteroids; Cytotoxic activity; Pyridine.