3.5-Dichloro-6-phenyl-2(H)-1,4-oxazin-2-one 3, 5-chloro-3,6-dimethyl-2(H)-1,4-oxazin-2-one 4, 5-chloro-6-methyl-3-phenyl-2(H)-1.4-oxazin-2-one 5 and 5-chloro-3.6-diplienyl-2(H)-1.4-oxazin-2-one 7, are ambident azadieries reacting efficiently and selectively with both electron rich and electron poor dienophiles. (C) 2004 Elsevier Ltd. All rights reserved.
Stereoselective Transformation of 2H-1,4-Oxazin-2-ones into 2,(2),5,5-Tri- and Tetrasubstituted Analogues of cis-5-Hydroxy-2-piperidinemethanol and cis-5-Hydroxy-6-oxo-2-piperidinecarboxylic Acid
2,(2),5,5-Tri- and tetrasubstituted analogues of 5-hydroxy-2-piperidinemethanol and 5-hydroxy-6-oxo-2-piperidinecarboxylic acid have been prepared via Diels-Alder reaction of 3-substituted 2H-1,4-oxazin-2-ones with ethene followed by functional group transformation of the resulting imidoyl chloride and lactone groups. Some of the 2-piperidinemethanol products are converted further into potential substance P antagonists. (C) 2000 Elsevier Science Ltd. All rights reserved.