102734-15-6Relevant academic research and scientific papers
An improved and stereoselective route to all-cis-2,6-disubstituted 4-hydroxypiperidines from accessible 4-substituted 4-N-benzylaminobut-1-enes
Varlamov, Alexey,Kouznetsov, Vladimir,Zubkov, Fedor,Chernyshev, Alexey,Shurupova, Olga,Vargas Mendez, Leonor Y.,Palma Rodriguez, Alirio,Rivero Castro, Juliette,Rosas-Romero, Alfredo J.
, p. 771 - 783 (2007/10/03)
The reaction between allylmagnesium bromide and imines 5a-l leads to the corresponding 4-substituted 4-N-benzylaminobut-1-enes 6a-1, which were oxidized in a regioselective manner to the alkenylnitrones 7a-l. The intramolecular 1,3-dipolar cycloaddition of these nitrones gave 2-spiroannulated or 2-substituted 6-exo-phenyl-1-aza-7-oxabicyclo[2.2.1]heptanes 8a-j. Reductive cleavage of the N-O bond of the obtained bicycles afforded the diverse substituted 4-hydroxypiperidines 9a-h in good yields. This stereoselective approach allowed the preparation of all-cis-4-hydroxy-6-phenyl-2-nonylpiperidine (9i), a close analogue of dendrobatid frog alkaloid 241D.
Stereoselective intramolecular nitrone cycloaddition in the synthesis of Lasubine II.
Hoffmann, Reinhard W.,Endesfelder, Andreas
, p. 1823 - 1836 (2007/10/02)
The intramolecular cycloaddition of α-substituted N-alkenylnitrones 2 leads to the 7-oxa-1-azanorbornanes 6,7, and 8 with a selectivity of ca. 80percent in favor of the exo,exo-disubstituted compound 6.The latter can be reduced to give the all-cis-2,6-disubstituted 4-hydroxypiperidines 4 which are key compounds for the synthesis of certain alkaloids as demonstrated by the synthesis of lasubine II.
