Reaction of monothiobenzil with trimethyl phosphite and dimethyl phenylphosphonite

1. The reaction of monothiobenzil with trimethyl phosphite and dimethyl phenylphosphonite gave the 2,2,2-trimethoxy-4,5-diphenyl- and 2,2-dimethoxy-2,4,5-triphenyl-1,3,2-oxathiaphospholenes, which are the first members of the monocyclic 1,3,2-oxathiaphospholenes. 2. The hydrolysis of the obtained phosphoranes results in the cleavage of both the P-O and the P-S bond, with a predominant cleavage of the latter. © 1976 Plenum Publishing Corporation