2-Cyano-. DELTA. 3-piperideines. 12. Stereochemistry of formation of N-benzyl-2-cyano-. DELTA. 3-piperideines and facile isomerization on alumina to 2-cyano-. …

…, JR Romero, DS Grierson, HP Husson

Index: Bonin, Martine; Romero, Jose Ricardo; Grierson, David S.; Husson, Henri-Philippe Journal of Organic Chemistry, 1984 , vol. 49, # 13 p. 2392 - 2400

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Citation Number: 45

Abstract

The reaction of the piperideine N-oxides la-f with trifluoroacetic anhydride in CH2C12 at 0" C (Polonovski-Potier reaction) led to the formation of the N-benzyl-2-cyano-A3-piperideines 3a- f. Epimeric mixtures were obtained for the amino nitriles 3b, c, f bearing an alkyl substituent at C-6. On examination of the'H and 13C NMR spectra for these mixtures, it was found that both the trans-A and cis-B epimers preferred conformations wherein the cyano group was ...