Enantiodivergent Approach to the Synthesis of <i>Cis</i>-2,6-Disubstituted Piperidin-4-ones
作者:Alejandro Lahosa、Miguel Yus、Francisco Foubelo
DOI:10.1021/acs.joc.9b01008
日期:2019.6.7
β-amino ketone derivatives were synthesized by decarboxylative Mannich reaction of chiral N-tert-butanesulfinyl imines with β-keto acids and were subsequently transformed into cis-2,6-disubstituted piperidin-4-ones through an organocatalyzed condensation with aldehydes. Both enantiomers were accessible from the same precursors by inverting the order in the reaction sequence of the aldehydes involved
Facile Synthesis of 4-Piperidones by Condensation of an α,β-Unsaturated Ketone, an Aldehyde and Ammonia: Synthesis of the<i>Dendrobatid</i>Frog Alkaloid 241D
作者:Michael W. Edwards、H. Martin Garraffo、John W. Daly
DOI:10.1055/s-1994-25665
日期:——
A one-step reaction of an α,β-unsaturated ketone (3-penten-2-one, 1), an aldehyde (decanal, 2) and an amine (ammonia) afforded mainly the cis-isomer of (±)-2-methyl-6-nonyl-4-piperidone (3). Sodium borohydride reduction afforded as the major product (±)-cis,cis-4-hydroxy-2-methyl-6-nonylpiperidine (4), identical in NMR and IR spectra to the (+)-piperidine 241D isolated from skin extracts of a dendrobatid frog. The reaction was shown to be generally applicable for the synthesis of 2,6-disubstituted 4-piperidones.