Enediyne chemistry has gained prominence in recent years in view of the presence of the moiety in several naturally occurring antitumor antibiotics. 1 Thermally activated cycloaromatization to form 1, 4-dehydrobenzene diradical (Bergman cyclization) is of special interest as the process has been implicated in the DNA-cleaving ability of many natural products and synthetic analogues. 2 Photoinduced dimerization, 3 cis-trans isomerization, ...
