7-Methyl-2,3,4,5-tetrahydro-1,4-oxazepin-5-one and the dioxepinone analogue: diastereofacial selectivity in catalytic hydrogenation and the explanation
7-Methyl-2,3,4,5-tetrahydro-1,4-oxazepin-5-one and the dioxepinone analogue: diastereofacial selectivity in catalytic hydrogenation and the explanation
Catalytic hydrogenation of the title compound proceeds from the site anti to the 7-methyl group to give the cis-dimethyl derivative; a possible stereoelectronic effect accounting for this selectivity is proposed based on the conformational analysis of the substrate by X-ray crystallography.