ABSTRACT
Ring cleavage transforms intrinsically inactive herbicides to herbicidally active products. For example, methazole, an oxadiazolidine, is converted by the r ing cleavage mechanism to the Photosystem I I inhibitor D C M U [l-(3,4-dichlorophenyl)-3-methyl urea]. Similarly, buthidazole, w i t h an imidazolinone ring, also undergoes r ing cleav age to yield an active N-methyl urea.
