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.
δ,δ-不饱和酮(3-戊烯-2-酮,1)、醛(癸醛,2)和胺(氨)的一步反应主要得到了(±)-2-甲基-6-壬基-4-哌啶酮(3)的顺式异构体。硼氢化钠还原反应的主要产物是(±)-顺式、顺式-4-羟基-2-甲基-6-壬基哌啶(4),其核磁共振和红外光谱与从一种石斛蛙的皮肤提取物中分离出的(+)-哌啶 241D 相同。该反应一般适用于合成 2,6-二取代的 4-哌啶酮。