2026-04-17T15:57:35Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1735712025-12-05T14:55:05Zcom_2072_1057col_2072_478917col_2072_478924

Studies on the Enantioselective Synthesis of E-Ethylidene-bearing Spiro[indolizidine-1,3′-oxindole] Alkaloids Yayik, Nihan Pérez Bosch, Maria Molins i Grau, Elies Bosch Cartes, Joan Amat Tusón, Mercedes Alcaloides Enantiòmers Compostos heterocíclics Síntesi orgànica Alkaloids Enantiomers Heterocyclic compounds Organic synthesis A synthetic route for the enantioselective construction of the tetracyclic spiro[indolizidine-1,3'-oxindole] framework present in a large number of oxindole alkaloids, with a cis H-3/H-15 stereochemistry, a functionalized two-carbon substituent at C-15, and an E-ethylidene substituent at C-20, is reported. The key steps of the synthesis are the generation of the tetracyclic spirooxindole ring system by stereoselective spirocyclization from a tryptophanol-derived oxazolopiperidone lactam, the removal of the hydroxymethyl group, and the stereoselective introduction of the E-ethylidene substituent by acetylation at the -position of the lactam carbonyl, followed by hydride reduction and elimination. Following this route, the 21-oxo derivative of the enantiomer of the alkaloid 7(S)-geissoschizol oxindole has been prepared. 2021-02-01T12:36:12Z 2021-02-01T12:36:12Z 2021-01-15 2021-02-01T12:36:12Z info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1420-3049 https://hdl.handle.net/2445/173571 705965 33467493 eng Reproducció del document publicat a: https://doi.org/10.3390/molecules26020428 Molecules, 2021, vol. 26, p. 428-442 https://doi.org/10.3390/molecules26020428 cc-by (c) Yayik, Nihan et al., 2021 http://creativecommons.org/licenses/by/3.0/es info:eu-repo/semantics/openAccess 15 p. application/pdf MDPI Articles publicats en revistes (Nutrició, Ciències de l'Alimentació i Gastronomia)