02285nas a2200253   4500008004100000022001400041245013800055210006900193260007300262300001000335490000800345520134600353653001101699653001701710653001801727653002001745653002301765653002001788100002901808700002701837700002601864700002101890856012001911       2011                        eng d  a0022-286000aFacile synthesis of N-benzylated 3-alkyl-2,6-diarylpiperidin-4-ones: Stereochemical investigation by 1D/2D NMR and single-crystal XRD0 aFacile synthesis of Nbenzylated 3alkyl26diarylpiperidin4ones Ste  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a44-560 v9903 a<p>A series of thirteen 1-benzyl-3-alkyl-2,6-diarylpiperidin-4-ones 14-26 were conveniently synthesized in high yields 87-92%. In order to find the impact on piperidone stereochemistry, beside the N-benzylation, methyl/ethyl/isopropyl groups at C-3 and halo/alkyl/alkoxy/benzyloxy groups on the phenyl rings at C-2/C-6 were introduced. All the synthesized compounds were characterized by mass, (1)H and (13)C NMR spectral studies. Of them, the 1-benzyl-3-ethyl-2,6-diphenylpiperidin-4-one 22 was completely characterized by 2D NMR techniques such as (1)H-(1)H COSY, (1)H-(13)C COSY and NOESY to assign the signals, unambiguously. The proton coupling constants and NOE correlations provided the complete stereochemistry of 22, which is further witnessed by its single-crystal XRD analysis. The NMR and XRD studies revealed that the compound 22 exists in a chair conformation with equatorial orientation of all the substituents in both solution and solid states. On the basis of their vicinal coupling constants, the chair conformation with equatorial orientation of the substituents at C-2, C-3, C-6 and N is proposed for all compounds 14-26; moreover, a considerable population of boat conformation also suggested for the compound 26 along with the predominant chair conformation, in solution. (C) 2011 Elsevier B.V. All rights reserved.</p>10a2D NMR10aConformation10aN-benzylation10aPiperidin-4-one10asingle-crystal XRD10aStereochemistry1 aDindulkar, Someshwar, D.1 aParthiban, Paramasivam1 aPuranik, Vedavati, G.1 aJeong, Yeon, Tae  uhttps://library.ncl.res.in/content/facile-synthesis-n-benzylated-3-alkyl-26-diarylpiperidin-4-ones-stereochemical-0