SEMINARIO QUÍMICA ORGÁNICA 27-4-26 EXPOSITOR : Qco. Arturo Mendoza Salgado TÍTULO : " Total Synthesis of (±)-Cristaxenicin A: Construction of Nine-Membered Ring by Eschenmoser–Claisen/Cope Rearrangement Cascade ". FUENTE : W.Kiuchi, Y.Tsunoda, K.Ishikura, K.Kato, J.Takino, T.Suzuki, K.Tanino, Angew. Chem. Int. Ed. 2026 , 65 , e24855. https://doi.org/10.1002/anie.202524855 . DÍA, HORA y LUGAR : Lunes 27 de abril de 2026, 14:00 h, Aula de graduados y virtual. Modalidad virtual, Link : meet.google.com/wpi-ujuz-rok. Resumen : Cristaxenicin A, a natural marine product with a skeleton consisting of a nine-membered carbocycle fused with a dihydropyran ring, displays strong antiprotozoal activity against Leishmania amazonensis and Trypanosoma congolense. The synthesis of cristaxenicin A is challenging because of its unique oxidation pattern at C11 and C20, the cis-cyclononane with a C5─C6 double bond, and the C1─C19 alkene moiety functionalized ...
SEMINARIO QUÍMICA ORGÁNICA 20-4-26 EXPOSITOR : Dr. Ernesto G. Mata TÍTULO : " Total Syntheses of Bryostatins ". FUENTE : Guo, Q., Yang, Y., Zhang, H., Wang, D., Li, B., Jiang, D., ... & Song, Z. Angewandte Chemie , 2025 , 137 (14), e202423465. DÍA, HORA y LUGAR : Lunes 20 de abril de 2026, 14:00 h, Aula de graduados y virtual. Modalidad virtual, Link : meet.google.com/wpi-ujuz-rok. Resumen : Bryostatin 1 34, produced by a bacterial symbiont of the marine bryozoan Begula neritina, has shown promise for the treatment of Alzheimer’s disease. This work reports the divergent total syntheses of bryostatins, obtaining 1.5 g of bryostatin 1 in the final three steps. Key methods include Ni-catalyzed reductive cross-coupling, flow-assisted light-induced radical addition, and a Prins cyclization for cis-Z selectivity. The syntheses require 20–22 linear steps (33–35 total) with overall yields of 3.3–4.5%.