Stereoselective Total Synthesis of (-)-Pyrenophorin

Background: Homo and hetero dimers of macrodilacto cyclic compounds were observed frequently in nature and they were built with different types of functional groups, chemical skeletons and ring sizes. Natural products with macrodiolide frameworks are also known to exhibit a wide range of biological properties including antibiotic, antifungal, antihelmintic, phytotoxic, and antileukemic activities. The main aim of this paper was the stereoselective total synthesis of (-)-Pyrenophorin from commercially available starting material (S)-propylene oxide with high yields. Methods: Stereoselective total synthesis of (-)-Pyrenophorin was done by hydrolytic kinetic resolution, Wittig olefination followed by Mitsunobu reaction. Results: The disconnection approach analysis (retrosynthetic) of (-)-Pyrenophorin envisions that it would be synthesized through the hydroxyl-acid via cyclo dimerisation under the Mitsunobu reaction conditions and followed by deprotection of cyclic ketals. Hydroxy-acid would be achieved from alcohol, while the alcohol would be obtained from (S)-propylene oxide. Conclusion: The total synthesis of target molecules achieved from commercially available starting materials, soft reaction conditions, decrease of reaction conditions and high purities with large yields. These type of biologically potent target molecules total synthesis was very important in industrial point of view.