89873-67-6Relevant academic research and scientific papers
Modified fry cyanation of a chiral pyridinium salt: Asymmetric syntheses of (-)-coniine and (-)-solenopsin A
Vu, Van Ha,Jouanno, Laurie-Anne,Cheignon, Adele,Roisnel, Thierry,Dorcet, Vincent,Sinbandhit, Sourisak,Hurvois, Jean-Pierre
, p. 5464 - 5474 (2013/09/02)
The synthesis of chiral 2-cyano-Δ4-tetrahydropyridine 5 was carried out in 85 % yield through a modified two-step Fry reductive cyanation of pyridinium salt (+)-3c that used lithium triethylborohydride as the hydride donor. An alkylation-reduction sequence provided 2-alkyl-substituted tetrahydropyridines (+)-10a and (+)-10b in 72-75 % yield after chromatographic purification. This protocol has been applied to the asymmetric syntheses of piperidine alkaloids (-)-coniine and (-)-solenopsin A. The two-step reductive cyanation of chiral pyridinium salt (+)-3c afforded α-amino nitrile 5 in 85 % yield, which underwent an alkylation-reduction sequence followed by removal of the chiral moiety to yield the hemlock alkaloid (-)-coniine as its mandelate salt (>99:1 er). This reaction sequence was also used for the synthesis of the trans-2,6-disubstituted piperidine alkaloid (-)-solenopsin A. Copyright
2-Cyano-Δ3-piperideines. 12. Stereochemistry of Formation of N-Benzyl-2-cyano-Δ3-piperideines and Facile Isomerization on Alumina to 2-Cyano-Δ4-piperideines. A Potentially General Route to the Synthesis of 2,6-Disubstitute
Bonin, Martine,Romero, Jose Ricardo,Grierson, David S.,Husson, Henri-Philippe
, p. 2392 - 2400 (2007/10/02)
The reaction of the piperideine N-oxides 1a-f with trifluoroacetic anhydride in CH2Cl2 at 0 deg C (Polonovski-Potier reaction) led to the formation of the N-benzyl-2-cyano-Δ3-piperideines 3a-f.Epimeric mixtures were obtained for the amino nitri
