Alcohol modification procedure

The above procedure may also be carried out in the presence of 1 ml. of dry pyridine with some alcohols improved yields may be obtained by this modification. 

Dianion formation from 2-methyl-2-propen-l-ol seems to be highly dependent on reaction conditions. Silylation of the dianion generated using a previously reported method was unsuccessful in our hands. The procedure described here for the metalation of the allylic alcohol is a modification of the one reported for formation of the dianion of 3-methyl-3-buten-l-ol The critical variant appears to be the polarity of the reaction medium. In solvents such as ether and hexane, substantial amounts (15-50%) of the vinyl-silane 3 are observed. Very poor yields of the desired product were obtained in dirnethoxyethane and hexamethylphosphoric triamide, presumably because of the decomposition of these solvents under these conditions. Empirically, the optimal solvent seems to be a mixture of ether and tetrahydrofuran in a ratio (v/v) varying from 1.4 to 2.2 in this case 3 becomes a very minor component. 

Benzoylene urea has been prepared by passing cyanogen into a solution of anthranilic acid in alcohol and hydrolyzing the resulting 2-ethoxy-4-ketodihydroquinazoline, by fusing anthranilic acid with urea, and by the action of aqueous cyanic acid on anthranilic acid. The procedure described is adapted from that of Bogert and Scatchard with several modifications. 

N -Ethyl-jK-toluidine has been obtained by passing m-toluidine and ethyl alcohol over a catalyst at high temperatures,1 and by the use of ethyl />-toluenesulfonate 2 as an alkylating agent. The present method of purification is a modification of a general procedure for secondary amines developed by Diepolder.3... 

The procedure described here is a modification of one involving the thermal fragmentation of 1-adamantyl hypoiodite and cycliza-tion of the resulting iodo ketone/ By means of this procedure, 4-protoadamantanone is obtained from 1-adamantanol with consistent yields in the range of 71 to 82% and a purity greater than 98%. This method is also applicable to the preparation of other polycyclic ketones from the related bridgehead alcohols with a-bridges of zero, one, or two carbon atoms (see Table I). 

Synthesis of optically pure compounds via transition metal mediated chiral catalysis is very useful from an industrial point of view. We can produce large amounts of chiral compounds with the use of very small quantities of a chiral source. The advantage of transition metal catalysed asymmetric transformation is that there is a possibility of improving the catalyst by modification of the ligands. Recently, olefinic compounds have been transformed into the corresponding optically active alcohols (ee 94-97%) by a catalytic hydroxylation-oxidation procedure. 

Several modifications of procedures based on halophosphonium ion have been developed. Triphenylphosphine and imidazole in combination with iodine or bromine gives good conversion of alcohols to iodides or bromides.22 An even more reactive system consists of chlorodiphenylphosphine, imidazole, and the halogen,23 and has the further advantage that the resulting phosphorus by-product diphenylphosphinic acid, can be extracted with base during product workup. 

The method constitutes a simple preparation of ethanol-in-soluble cinnamic acids, of a high degree of purity when compared with the Perkin reaction 6 or the usual procedure for the Doebner reaction,6 which uses a large excess of pyridine. A useful modification of this reaction is to warm the reactants on a steam plate in the absence of alcohol.7 8... 

The complexes [(n-C4H9)4N]2[MS4C4(CN)4], where M = Co, Ni, Cu, and Rh are isomorphous, and mixed single crystals can be grown very easily using the acetone-isobutyl alcohol solvent pair and only slight modifications of the recrystallization procedure. 

The carbamates of tertiary acetylenic alcohols have also been made by reaction of these alcohols with sodium cyanate in tri-fluoroacetic acid.9 The yields by this procedure are significantly lower than those obtained by the present modification, which is essentially that described by Loev and Kormendy.5... 

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