Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0506, USA. tmcmorris@ucsd.edu
Bicyclic and tricyclic analogues of anticancer sesquiterpene illudin S have been synthesized. These contain a spiro-cyclobutane instead of spiro-cyclopropane structure. The cytotoxicity of the former is less than that of the corresponding cyclopropane-containing compounds.