10.1016/j.tet.2011.03.045
The research focuses on the nucleophilic ring-opening reactions of 1-aralkyl-3,4-epoxypiperidines with various aliphatic and aromatic amines. The main objective was to develop a short-step synthesis method for 4-fluorobenzyltrozamicol and novel anilidopiperidines with high regiocontrol. The study utilized different solvents, including protic solvents like 2-propanol and acetonitrile, with and without the assistance of metal salts such as LiBr and LiClO4 to achieve high regioselectivity in the formation of 3-amino-piperidin-4-ols and 4-amino-piperidin-3-ols. The experiments involved the synthesis of 1-aralkyl-3,4-epoxypiperidines, their ring-opening with amines, and subsequent transformations to form the desired compounds. The research also explored the steric effects on regioselectivity and provided structural correlations through NMR analysis. The products were characterized using techniques such as HPLC, NMR, and mass spectrometry, with detailed analyses of the ratios of regioisomers and the yields of the synthesized compounds.