Neurons on steroids: A stereoselective synthesis of the neuritogenic steroid lactone withanolide A was achieved by singlet oxygen ene reaction, Wharton transposition, a Corey–Seebach homologation, and a vinylogous aldol reaction. Biological evaluation demonstrated neurite outgrowth, which supports the potential neuritogenic role of this compound in traditional Indian medicine.

The exploration of different routes leading to the stereoselective synthesis of the neuritogenic steroid withanolide A is reported in full detail. Notable features of the synthesis include a Corey-Seebach homologation, a vinylogous aldol reaction, a singlet oxygen Schenck-ene reaction, and finally, a latestage Wharton transposition. Semi-synthetic elaboration of the natural product resulted in 15 derivatives allowing a better understanding of its inherent reactivity pattern as well as its biological properties related to neuronal differentiation and neurite outgrowth.

The first total syntheses of the piericidin related natural products Mer-A2026B and JBIR-02 are reported. Key features of the synthetic approach involve an Ir-catalyzed one-pot C-H activation/oxidation procedure for the preparation of the hydroxypyridine, a vinylogous Mukaiyama aldol reaction, and a final Negishi cross-coupling of an advanced pyridine derivative with an allylic side chain precursor. In addition, the absolute configuration of Mer-A2026B (9R,10R) and JBIR-02 (9R,10R) was established.

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Aiming to control neurite formation and navigate the axonal growth by an extrinsic guidance, we report on the design, synthesis and biological evaluation of caged retinoids. Agonists of RARβ have been temporarily blocked either by the [(α-methyl-2-nitropiperonyl)oxy]carbonyl (MeNPOC) group or by immobilization using nitrocatechol linkers on TiO2 particles. Release on demand has been achieved by release under UV irradiation, leading to the biologically active compounds, which have been shown to induce neuronal differentiation and neurite outgrowth.