... Tetrahedron Letters. Volume 39, Issue 8, 19 February 1998, Pages 761–764. Cover image Cover image. ... see 3f Tetrahedron Lett., 37 (1996), p. 6025. ... For a review on the use of N-oxides, see: 5a Comprehensive Heterocyclic Chemistry, Vol. 2Pergamon Press (1984). 9. ...