The first regio- and diastereoselective synthesis of homochiral perhydroimidazoisoxazoles via the 1,3-dipolar cycloaddition of imidazoline 3-oxides with (1S)- (-)-beta-pinene


Coskun N. , Tat F., Guven O.

TETRAHEDRON-ASYMMETRY, vol.12, no.10, pp.1463-1467, 2001 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 12 Issue: 10
  • Publication Date: 2001
  • Doi Number: 10.1016/s0957-4166(01)00270-1
  • Title of Journal : TETRAHEDRON-ASYMMETRY
  • Page Numbers: pp.1463-1467

Abstract

The 1,3-dipolar cycloaddition of imidazoline 1-oxides I with (1S)-(-)-beta -pinene proceeds regio- and diastereoselectively to give homochiral perhydroimidazoisoxazole derivatives 3 in high yields in the cases of imidazoline 3-oxides 1a-e but in low yields in the reactions of If g. The preferred attack of (1S)-(-)-beta -pinene to the cyclic nitrone was shown to be anti-endo. The reaction of racemic nitrones (+/-)-1f g with the homochiral beta -pinene gave the adduct from (lie (S)-nitrone and the corresponding imidazole. The adducts 3 Undergo retro-1,3-dipolar cycloaddition when heated in the condensed phase or in diphenyl ether to give the corresponding imidazole and beta -pinene. (C) 2001 Elsevier Science Ltd. All rights reserved.