Pure and Applied Chemistry

Abstract: A new strategy has been developed for the synthesis of naturally occurring 6‑alkenyl phenolic acids and 3-alkylpyridine alkaloids of biological importance. This strategy makes use of the proper substituted aryl or pyridyl sulfone as the potent intermediate. A carbanion was generated from the sulfone by treating it with NaH in dimethylformamide (DMF) at –5 °C and was used for alkylation reaction with alkyl/alkenyl bromide in DMF at 0 °C to give product, which, on reduction with sodium-amalgam, yielded the desired natural product. Using this methodology, we have synthesized 11 natural 6-alkyl/alkenyl salicylic acids, which were known to possess strong antimicrobial activities against many pathogens and had also shown molluscicidal activity against the snail Biomphalaria glabrata. This methodology was also extended to synthesize two natural 3-alkylpyridine alkaloids that were known to possess strong cytotoxic activity against P-388 murine leukemia cells with IC₅₀ values of 1–2.3 μg/ml. Taking leads from these natural products, we have also synthesized a number of related compounds in order to find a potential drug candidate for the future. This paper presents the highlights of the work done on the synthesis of these two classes of compounds.