Speaker: Prof. Dattatraya Dethe
Department of Chemistry,
Indian Institute of Technology Kanpur,
Kanpur 208 016 (UP), INDIA
Title: "New Reactivity and Strategic Design in the Synthesis
of Diterpenoids and Limonoids."
Day and Date: Tuesday, August 11, 2026
Time: 16.00 Hrs.
Venue: Room no. 350, Chemistry Department
Second floor, Annex
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Hosted by Prof. Suvarn S. Kulkarni
Abstract The power of chemical synthesis lies not only in the reactions that stitch molecules together, but in the strategic vision that guides their assembly. A well-crafted synthetic strategy can illuminate the logic of complex molecular architectures, enable access to entire families of natural products, and inspire new reactivity along the way. In this presentation, I will highlight the strategic and tactical principles that have shaped our group’s efforts toward architecturally diverse natural products.
I will begin by discussing our recent efforts which have expanded into the diterpenoid and limonoid families. In the diterpenoid arena, we achieved the synthesis of three atisane-type natural products and completed the first enantioselective total syntheses of three rearranged ent-trachylobane diterpenoids: (–)-wallichanol A, (–)-wallichanol B, and (–)-sanguinolane. These syntheses showcase a novel intramolecular [2+2] cycloaddition to forge a previously unknown tricyclo[3.3.1.0²,⁷]nonane core, along with strategically deployed hydrogen-atom transfer reductions, Robinson annulation, and late-stage aerobic oxidations.
Finally, I will discuss our emerging program in limonoid synthesis, centered on a divergent, enantioselective route from Wieland-Mischer and Hajos–Parrish ketone derivatives. Key to this platform is a sterically assisted hydroboration–boron chain-walking–oxidation sequence that enables remote C–H hydroxylation in densely functionalized frameworks. This approach has delivered the total synthesis of (+)-azadiradione and related congeners and provides a unified strategy toward limonoid families.
Together, these studies illustrate how strategic design—guided by biosynthetic intuition, unified building blocks, and new reactivity—can enable efficient entry into complex natural product space and open opportunities across diverse structural classes.