The optical activity of 1-phenylethanol from benzaldehyde and methyl chloride Grignard reagent coordinated with (+)2,3-dimethoxybutane is about one fourth of that found for the same product when bis-methyimagnesiun is the reagent. The difference has been attributed to the relative coordinating power of magnesium chloride versus the optically active ether.Grigilard reagents usually contain bound halogen because they are commonly prepared by corrosion of magnesium by means of an organic halide. Indeed, this process historically defines the reagent. However, these reagents may be rendered halogen free by the dioxane precipitation technique of the Schlenks (I) and the resultant solution of bis-organomagnesium also has been considered to be a Grignard reagent. We adhere to this extended definition largely because the amount of magnesium halide in a Grignard reagent is dependent on the type of halide and upon the method of reagent preparation. Thus a reagent series may exist with bis-organomagnesium a t one extreme and Grignard reagent saturated with magnesium halide a t the other. Such a series would be important only if there is a difference in reactivity in time or type between the extremes. Interest in these differences has increased during recent years (2, 3, 4). In this report the difference in coordination of the organometallic compound with an ether has been investigated.The method we used is the induction of optical activity in a product of Grignard reagent addition (5, 6, 7) by use of (+)2,3-diinethoxybutane to effect an asyinrnetric synthesis. We synthesized 1-phenylethanol from methyl Grignard reagent and benzaldehyde and compared yields and optical rotation when either bis-methylmagnesium or nlethyl chloride Grignard reagent is used. For the coinparison to be meaningful it is important that the first of these reagents be quite free from halide. Mosher (4) found it difficult to attain this condition. By contrast, our precipitate initially contains not only the halide in toto but also some of the halogenfree complex. T o obtain a reasonable yield of bis-methylmagnesium we must wash the precipitate thoroughly. Subsequently a small amount of white precipitate tends to appear in the solution, presumably because of temperature variations. I-Io~vever, both the solution and the slight precipitate are halogen free by silver halide test. The difference between our results and those of ibIosher may be due to our specific reagent or else to the dioxaneGrignard ratio or to our use of heat during the precipitation.The halide-free solution contains bis-methylmagnesium dioxanate or dioxanateetherate, so these ethers must be removed to ensure that the optically active ether will be fully effective. htlost of the diethyl ether is removed easily a t 50 "C under 1 atm of nitrogen, leaving a solid residue. Co~nparison of the weight of this residue with the basic magnesium equivalence, according to titration (S), indicates a composition of one-half dioxane per inole of bis-inethylmagnesium.

The de~netalation of diorganosubstituted mercury con~pounds is catalyzed by peroxides. When organonlercuric salts are present this demetalation leads to formation of mercurous salt plus mercury. This latter combination has been found to be a catalyst for the redistribution reaction of bis-mercurials. I t is suggested that all previously reported catalysts for this reaction operate by formation of the mercurous salt -mercury combination. Equilibration studies with this co~nbinatioll a s catalyst indicate that random exchange is not general for the redistribution reaction of mercury compounds.The equilibration of organic substituent groups among mixtures of bis-organolead, organotin, and organomercurials has been summarized (1) by Calingaert, who coined the name "redistribution reaction" originally for the equilibration of tetraalkyllead compounds in which the substituents were homologous or structurally isomeric (2). He applied the name also to the simpler equilibration of bis-mercurials (3).Obviously these reactions are, a t most, "distributions"; the redundancy was unfortunate but a t least it accentuated Calingaert's discovery that the "redistribution" was statistically random and unrelated to the structure of the substituent groups. Also, he demonstrated t h a t the redistribution was catalyzed by metal halides and organometallic halides, including those related to the organometallic compounds that he was "redistributing".Despite the mass of evidence relating to the redistribution reaction and its catalysis, we have found that for bis-mercurials i t is quite erratic. For example, 4-cyclohexylmercuritoluene is recovered unchanged when it is treated in solvents such a s methanol, petroleum ether, benzene, or dioxane with 1-5 inole % of the recommended (3) catalysts: boron fluoride etherate, aluminum chloride, magnesium bromide hydrate, zinc chloride, and cyclohexylmercuric chloride a t room temperature. On the other hand, a moderately pure sample decomposes when heated without either solvent or any of the recommended catalysts, giving bis-4-tolylinercury. Likewise, for one operator, 2-butylmercuri-4-toluene in inethanol or petroleum ether has been heated under reflux for 15 h without alteration in presence of mercuric bromide or 2-butylmerc~iric bromide. For another, a methanol solution of the substance has reacted in 8 h under reflux without added catalyst to give a 42Yo yield of bis-4-tolylinercury and a 47Yo yield of bis-2-butylmercury. Similar anomalies have been found for benzylinercuriethane.Part of the reason for this lack of reliability has become evident during our attempts to isolate and preserve bis-cyclohexyln~ercury in a pure state for determination of its dielectric constant (4). T h e instability of this substance is apparent in its use (5) a s a catalyst in the hoinopolar polyn~erization of vinyl acetate. We find that the recently crystallized white substance turns grey within a n hour in air. If it is vacuum distilled immediately after crystallization, some decomposition occurs during t...