reported. The reaction of dimagnesium salts of ketone hydrazones with diselenium dichloride affords an intermediate tentatively assigned as tetraselenides, which are converted into selenoketones by heating in the presence of tributylamine. A comparative study on the reactions of 1,1,3,3-tetramethyl-2-indanselone and the corresponding thioketone with Grignard and organolithium reagents have been carried