Synthesis of di- and cis-triaryl-3a,4,5,6-tetrahydroimidazo[1,5-b]isoxazoles and their ring-opening reactions


Coskun N. , Tat F., Guven O.

TETRAHEDRON, vol.57, no.16, pp.3413-3417, 2001 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 16
  • Publication Date: 2001
  • Doi Number: 10.1016/s0040-4020(01)00184-3
  • Title of Journal : TETRAHEDRON
  • Page Numbers: pp.3413-3417

Abstract

The Delta (3)-imidazoline 3-oxides I undergo diastereoselective cycloaddition with dimethyl acetylenedicarboxylate 2 to give 3a,4,5,6-tetrahydroimidazo[1,5-b]isoxazoles 3. Thermally and base induced ring-opening reactions of compounds 3 were demonstrated. cis-6-Phenyl substituted adducts 3d,e undergo ring opening with secondary but not with ternary amines. The same adducts undergo regio- and diastereoselective Michael addition with sodium methoxide to give 2-methoxy-3a,5,6-triphenyl-hexahydro-imidazo[1,5-b]isoxazole-2,3-dicarboxylic acid dimethyl esters 6. (C) 2001 Elsevier Science Ltd. All rights reserved.