The synthesis and structure of some 4-aryloxymethyl-2,2,6,6-tetramethyl-4-piperidinol and 4-aryloxymethyl-4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy derivatives

Abstract

The synthesis of 5,5,7,7-tetramethyl-1-oxa-6-azaspiro[2.5]octane and modified synthesis of 5,5,7,7-tetramethyl-1-oxa-6-azaspiro[2.5]oct-6-yloxy are described. Reaction of these spiro-oxiranes with phenols gave corresponding 4-aryloxymethyl 4-piperidinols and their 1-piperidinyloxy derivatives. The same products have also been obtained by reaction with ethanol. The crystal structures of two derivatives: 4-phenoxymethyl-2,2,6,6-tetramethyl-4-piperidinol (3a, 2880 reflections, R = 0.054) and 4-phenoxymethyl-4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (6a, 4395 reflections, R = 0.084) have been determined. Piperidine rings are in a chair conformation in both compounds with the phenoxymethyl substituent in an equatorial position. The [Formula: see text] group is not planar, with the N—O bond inclined by 18.4° to the CNC plane. Although the space groups are different for these two compounds the molecules are packed in the crystal lattice in a topologically equivalent way.