Procedure, Gilman

TMEDA was added in 1 1 mole ratios to hydrocarbon solutions of the alkyllithium compound. The solutions were kept at a given temperature until gas evolution ceased. The dark, orange-brown solutions were analyzed using the Gilman procedure when complete reaction of the... 

The hydrolysis of the reaction mixture and subsequent separation of the acid is the procedure given by Gilman and Parker (Org. Syn. 5, 25). Sulfuric acid should be added during the hydrolysis as long as any particles of magnesium are present. The water layer does not become clear, due to solidification of the organic acid. 

The preparation of iodo (trimethyl) platinum (IV) of empirical formula PtI(CH3)3 was first reported by Pope and Peachey.1 The substance was produced by the reaction between platinum (IV) chloride and methylmagnesium iodide. Gilman et al.2 have repeated this method of preparation to give a 45% yield and have identified some of the side products of the reaction. Various starting materials and procedures have been used by... 

Representative procedure forthecouplingofan alkenyliodonium tosylate with a Gilman cuprate ( )-(2-bromoprop-1 -enyl)benzene [64] To a stirred suspension of Cp2Zr(H)Cl (0.360 g, 1.4 mmol) in THF (6 mL) was added phenyl(phenylethynyl)iodonium tosylate (0.476 g,... 

Butyllithium in pentane was purchased from Alfa Products, Morton/Thiokol Inc. and was titrated by the method of Gilman and Cartledge.23 The checkers used a 1.56 N hexane solution purchased from Mitsuwa Chemical Co. after titration by th Kofron-Baclawski procedure.215... 

The reaction can be alternatively carried out with TMSC1 as a Lewis acid and oiganocuprates [53]. (—)-Dihydro-pinidine, the enantiomer of an alkaloid from Pinas jeffrei, has been synthesized in excellent overall yield following this method. Piperidinone 46a was treated with Gilman s cuprate and trimethylsilylchloride in THF at -78 °C, such that the 2,6-disubstituted piperidinone 49a was obtained in high yield and diastereoselectivity. Its carbonyl group was reduced in a two-step procedure via formation of the dithiolane and subsequent desulfurization with Raney nickel. 

Available from Ventron Corporation, Alfa Products, Beverly, MA 01915. t The molarity of the butyllithium solution may be checked before use by the procedure devised by Gilman.3 This involves careful hydrolysis of a measured sample using excess distilled water, followed by titration against standard hydrochloric acid solution with phenolphthalein as indicator. Since the butyllithium solution may contain some lithium hydroxide, it is necessary to carry out an identical titration of a sample which has undergone complete reaction with benzyl chloride in order to determine the lithium hydroxide present. From the difference between the two titrations, the molarity of the butyllithium may be calculated. 

Scheme 9.17). The macrocycle (A) of Scheme 9.1 is the dpp-incorporating 30-membered ring 8 used earlier for making catenanes (see Protocol 5) it is sufficiently small to prevent release of the bis-porphyrin dumbbell. The preparation of 22+ takes place in seven steps.1819 One of the starting materials is 4-lithiotoluene 13, which may be obtained by direct interaction of an excess of freshly cut lithium with 4-bromotoluene 12 in ether under argon at reflux (Scheme 9.10).12 The resulting organolithium compound is titrated by the double titration method described by Gilman et alP The experimental procedure is very similar to that described in Protocol 1.

Carboxylic amides. Gilman has extended the procedure of Corey et at. (2, 261) for oxidation of allylic alcohols to carboxylic esters to the preparation of carboxylic amides. Thus oxidation of aromatic and a,/ -unsaturated aldehydes with Mn02 in the presence of sodium cyanide and an amine gives the corresponding carboxylic amides in high yield. In the absence of sodium cyanide, high yields of nitriles are formed from aldehydes, ammonia, and manganese dioxide. 

Tetraphenyllead can be made by the procedure of Gilman, Summers, and Leeper alternatively, the commercial product, available from the Aldrich Chemical Company, Milwaukee, Wis., can be used without further modification. 

The actual isolation of beryllium dialkyls in a pure state has only just been accomplished by Gilman and Schulze, and their work throws doubt upon the accurac of that of previous investigators. Their method of procedure is the one suggested by Krause and Wendt. In 1926, Durand claimed to have prepared beryllium methyl iodide, but the work has since been disproved by Gilman and Schulze. These workers have isolated beryllium alkyl halides by heating beryllium, alkyl halides, and ether in the presence of catalysts, such as mercuric chloride, beryllium chloride, or free bromine. The first aryl compound, beryllium phenyl iodide, has been prepared by a similar process. 

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