A concise and efficient synthesis of tetrahydroquinoline alkaloids using the phase transfer mediated Wittig olefination reaction

• Published in: Tetrahedron letters Vol. 58; no. 33; pp. 3311 - 3315
• Main Authors: Diaz-Muñoz, Gaspar, Isidorio, Raquel Geralda, Miranda, Izabel Luzia, de Souza Dias, Gabriel Nunes, Diaz, Marisa Alves Nogueira
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 16.08.2017; Elsevier
• Subjects: Chemistry; Chemistry, Organic; Galipea officinalis; Phase transfer medium; Physical Sciences; Science & Technology; Tetrahydroquinoline alkaloids; Wittig reaction; Wittig reaction; Galipea officinalis; Phase transfer medium; Tetrahydroquinoline alkaloids; ASYMMETRIC-SYNTHESIS; QUINOLINES; ALLYLIC AMINATION; ANGUSTUREINE; GALIPININE; (+)-ANGUSTUREINE; (+)-(S)-ANGUSTUREINE; GALIPEA-OFFICINALIS; HIGHLY ENANTIOSELECTIVE HYDROGENATION; ESTERS
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2017.07.044

[Display omitted] •The total synthesis of 1,2,3,4-tetrahydroquinoline alkaloids, was carry out in three steps and high yields.•The key step of this approach is based on an unusual Wittig reaction by using the phase transfer medium.•This protocol is compatible with chiral aldehydes. The present study describes the total synthesis of 1,2,3,4-tetrahydroquinoline alkaloids (±)-galipinine, (±)-cuspareine, (±)-galipeine and (±)-angustureine, in three steps and high yields (78%, 76%, 74%, and 66%, respectively) from common aldehyde and the ylide respectives. The key step of this approach is based on an unusual Wittig reaction by using the phase transfer medium (aq. NaOH/CH2Cl2 1:1 or t-BuOK/t-BuOH/CH2Cl2 1:1), affording olefinic intermediates in high yields.