Diastereoisomeric 2-aryl-6-methyl-3,4 (1,2-piperido)-oxazines

Abstract

The alkaloid sedridine (1) is formed stereospecifically by catalytic hydrogenation of optically active α-picolyl methyl carbinol (2). The levorotatory 1 gave on action of p-nitro benzaldehyde two μ-aryl oxazines, one crystalline and levorotatory, the other oily and dextrorotatory. This is the first example where both epimers of a μ-aryl oxazine could be detected. The configurations and the conformations of these isomers (10 and 11) and those of sedridine have been discussed in terms of their nuclear magnetic resonance spectra, with particular reference to spin-decoupling evidence.