... Advanced search. Other users also viewed these articles. Opens document download manager. Do not show again. Downloading zip file containing 3 articles... JavaScript is disabled on your browser. Please enable JavaScript to use all the features on this page. Tetrahedron Letters. Volume 33, Issue 15, 7 April 1992, Pages 1993–1996. Cover image Cover image. New Access to Spiranic β-Lactams. ... b) J. Cossy, C. Leblanc; Tetrahedron Lett., 30 (1989), p. 4531. ...