STUDIES OF REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES.: XXVIII. THE STRUCTURE OF ISOPROPYLIDENE GLYCEROL

1930 ◽  
Vol 2 (3) ◽  
pp. 214-217 ◽  
Author(s):  
Harold Hibbert ◽  
J. G. Morazain
Keyword(s):  
Methyl Iodide ◽  
Methyl Ether ◽  
Copper Sulphate ◽  
Silver Oxide ◽  
Condensation Product ◽  
Neutral Medium ◽  
Physico Chemical ◽  
Isopropylidene Glycerol

Isopropylidene glycerol, prepared in neutral medium by the action of anhydrous copper sulphate as condensing agent, was methylated with silver oxide and methyl iodide; the product yielded only glycerol α-methyl ether on hydrolysis, thus proving the absence of any six-membered ketal in the condensation product of glycerol and acetone.The properties of both glycerol α- and β-methyl ethers have been carefully redetermined.A table of the isomeric acetals and ketals summarising their physico-chemical constants is given, in view of their usefulness as "type compounds" in investigations relating to fats, carbohydrates and polysaccharides.

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES.: PART XXVI. STRUCTURE OF ACETONE GLYCEROL

1930 ◽  
Vol 2 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Harold Hibbert ◽  
J. G. Morazain
Keyword(s):  
Low Temperature ◽  
Methyl Ether ◽  
Neutral Medium ◽  
Satisfactory Explanation ◽  
Isopropylidene Glycerol

The condensation of acetone with glycerol has been carried out in a neutral medium, at a low temperature, and the product shown to consist entirely of the five-membered isopropylidene-glycerol ketal. Based on this fact, the use of the substance for the determination of the structure of fats is therefore warranted. Isopropylidene-glycerol and its acetate readily hydrolyse on heating with water.No satisfactory explanation can, as yet, be offered for the non-formation of the six-membered ketal under the conditions outlined.Acetone, as previously shown by other workers, is capable of forming a six-membered cyclic ketal with glycerol-β-methyl ether, dihydroxy acetone, pentaerythritol and certain carbohydrates.

ipso Nitration. XXIII. Reactions of cyclohexadiene adducts from nitration of 4-ethyltoluene in acetic anhydride

1981 ◽  
Vol 59 (15) ◽  
pp. 2314-2327 ◽  
Author(s):  
Alfred Fischer ◽  
George N. Henderson
Keyword(s):  
Sulfuric Acid ◽  
Acetic Anhydride ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Potassium Hydroxide ◽  
Silver Oxide ◽  
Aluminum Hydride ◽  
Trifluoroacetic Anhydride ◽  
Aqueous Methanol

The diastereoisomers of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate (1) and 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate (2) are stereospecifically reduced to the corresponding nitrocyclohexadienols with aluminum hydride. Each dienol is stereospecifically methylated to the corresponding methyl ether with methyl iodide, silver oxide, and potassium hydroxide. Acid-catalysed solvolysis of the acetates 1 and 2 results in the substitution of the acetate moiety by other nucleophiles and these reactions are not stereospecific. The products of rearomatization of dienyl acetates, dienols, and dienyl methyl ethers depend on the acidity and ionizing power of the solvents and are readily explained in terms of reactions involving a nitrocyclohexadienyl cation or acetoxy- (hydroxy-, methoxy-)cyclohexadienyl cation as key intermediates. In the 4-acetoxy-4-alkylcyclohexadienyl cation 1,2-migration of the acetoxyl group is more rapid than alkyl migration, but 1,2-alkyl migration is faster than migration of the hydroxyl or methoxyl groups in the corresponding cations. 1-Ethyl-4-methoxy-4-methylcyclohexa-2,5-dien-1-ol and 4-ethyl-3-nitrotoluene are significant minor products in the solvolysis of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dien-1-ol in aqueous methanol. Nitration of p-ethyltoluene in the presence of sulfuric acid or in trifluoroacetic anhydride gives a mixture of 4-ethyl-2-nitro- and 4-ethyl-3-nitrotoluene in a 2:1 ratio.

METHYLATION OF SUGAR DITHIOACETALS: IV. D-XYLOSE DIETHYL DITHIOACETAL

1962 ◽  
Vol 40 (10) ◽  
pp. 1899-1902 ◽  
Author(s):  
G. G. S. Dutton ◽  
Y. Tanaka
Keyword(s):  
Methyl Iodide ◽  
Methyl Ether ◽  
Silver Oxide ◽  
Partial Methylation ◽  
Tetrahydrofuran Solution

Partial methylation of D-xylose diethyl dithioacetal in tetrahydrofuran with methyl iodide and silver oxide yielded 2-, 3-, and 5-O-methyl-D-xyloses in the ratio of 20:10:1. The poly-O-methylated components were not examined. The 2-O-methyl-D-xylose was identified as the crystalline sugar and the 3-O-methyl ether as the phenylosazone and p-bromophenylosazone. An alternative preparation of the dithioacetal in tetrahydrofuran solution is described.

Lithiation of bridgehead positions in 3,6-bridged piperazine-2,5-diones

1982 ◽  
Vol 35 (11) ◽  
pp. 2289 ◽  
Author(s):  
FW Eastwood ◽  
D Gunawardana ◽  
GT Wernert
Keyword(s):  
Carbonyl Group ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Sodium Methoxide ◽  
Inductive Effect ◽  
Amide Nitrogen

2,5-Dimethyl-2,5 diazabicyclo[2,2,2]octane-3,6-dione can be lithiated at the 1,4 (bridgehead) positions with 2 equiv. of t-butyllithium at -78� and deuterated with D2O (Do, 11.2; Dl, 56.1 ; D2, 30.1%). With butyllithium and methyl iodide the 1,2,5-trimethyl and 1,2,4,5-tetramethyl derivatives are obtained. Treatment of dimethyl 2,6-diaminoheptanedioate dihydrochloride with sodium methoxide in boiling butanol gives 6,8-diazabicyclo[3,2,2]nonane-7,9-dione in 62% yield. N-Methylation of this compound yields 6,8-dimethyl-6,8-diazabicyclo[3,2,2]nonane-7,9-dione which can similarly be lithiated at the 1,5 (bridgehead) positions and deuterated with D2O (Do, 5.6; Dl, 70.8; D2, 23.6%). Lithiation with butyllithium and reaction with methyl iodide, benzyl iodide or bromomethyl methyl ether gives mono-and di-alkylated products at the 1,5-positions. The ability to lithiate the bridgehead positions in these compounds is attributed primarily to a combination of the inductive effect of the carbonyl group and dipole stabilization by the amide nitrogen.

METHYLATION OF SUGAR MERCAPTALS: II. L-ARABINOSE DIETHYL MERCAPTAL

1961 ◽  
Vol 39 (9) ◽  
pp. 1797-1800 ◽  
Author(s):  
G. G. S. Dutton ◽  
Y. Tanaka
Keyword(s):  
Methyl Iodide ◽  
Silver Oxide

Methylation of L-arabinose diethyl mercaptal in tetrahydrofuran with methyl iodide and silver oxide yielded mainly 2-O-methyl-L-arabinose and a trace of 5-O-methyl-L-arabinose. The identity of the major component was inferred by its behavior on electrophoresis and confirmed by the preparation of the crystalline amide. The polymethylated components were not examined. 2-O-Methyl-L-arabono-γ-lactone, previously known as a sirup, has now been obtained crystalline.

N-Methylamino acids in peptide synthesis. VII. Studies on the enantiomeric purity of N-methylamino acids prepared by various procedures

1977 ◽  
Vol 55 (5) ◽  
pp. 916-921 ◽  
Author(s):  
S. T. Cheung ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acid ◽  
Methyl Iodide ◽  
Peptide Synthesis ◽  
Liquid Ammonia ◽  
Silver Oxide ◽  
Sodium Hydride ◽  
Enantiomeric Purity ◽  
Amino Acid Analyzer ◽  
Pure Compounds ◽  
Optically Pure

The enantiomeric purity of N-methylamino acids and their derivatives obtained by various procedures has been examined by analysis with an amino-acid analyzer of the diastereomeric lysyl dipeptides formed by coupling them with a lysyl derivative. N-Benzyloxycarbonyl, and N-tert-butyloxycarbonyl,N-methylamino acids obtained by methylation of the parent derivative using sodium hydride and methyl iodide, and N-methylamino acids obtained by methylation of the p-toluenesulfonylamino acid followed by treatment with sodium in liquid ammonia, are optically pure. Compounds obtained by other procedures which include reductive alkylations or the use of silver oxide – methyl iodide are generally not optically pure.

A SYNTHESIS OF 1-HYDROXY-2-NAPHTHOIC NITRILE

1937 ◽  
Vol 15b (11) ◽  
pp. 480-485 ◽  
Author(s):  
John A. McRae ◽  
Léo Marion
Keyword(s):  
Ethyl Alcohol ◽  
Methyl Ether ◽  
Condensation Product ◽  
Neutral Product ◽  
Low Pressures

The neutral product of the condensation of phenylacetaldehyde with ethyl sodiocyanoacetate when distilled under low pressures loses the elements of ethyl alcohol and forms 1-hydroxy-2-naphthoic nitrile. This is identical with the synthetic substance prepared through a series of reactions from α-naphthol. The methyl ether has been prepared from both the synthetic substance and the product of the condensation. 1-Hydroxy-2-naphthoic nitrile can be coupled readily with p-nitrobenzenediazonium chloride. The evidence relating to the structure of the neutral condensation product is reviewed.

METHYLATION OF SUGAR DITHIOACETALS: V. D-MANNOSE DIETHYL DITHIOACETAL

1963 ◽  
Vol 41 (10) ◽  
pp. 2500-2503 ◽  
Author(s):  
G. G. S. Dutton ◽  
Y. Tanaka
Keyword(s):  
Methyl Iodide ◽  
Silver Oxide ◽  
The Other ◽  
Partial Methylation

Partial methylation of D-mannose diethyl dithioacetal in tetrahydrofuran with methyl iodide and silver oxide yielded 2-, 3-, and 6-O-methyl-D-mannose in the ratio of 12:1:1, respectively. The major component, 2-O-methyl-D-mannose, was characterized as the phenyl-hydrazone and the other isomers identified by electrophoresis. The Mg values of these mono-O-methyl ethers were recorded.

scholarly journals COMPARATIVE CHARACTERISTICS OF PHYSICO-CHEMICAL PROPERTIES OF DRUGS TOPICAL APPLICATION FOR THE PREVENTION OF COMPLICATIONS OF TOOTH EXTRACTION

2018 ◽  
Vol 14 (4) ◽  
pp. 64-70
Author(s):  
Ирина Костина ◽  
Irina Kostina ◽  
Вера Молвинских ◽  
Vera Molvinskikh ◽  
Надежда Белоконова ◽  
...  
Keyword(s):  
Tooth Extraction ◽  
Chemical Properties ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Bound State ◽  
Collagen Sponge ◽  
Model Systems ◽  
Neutral Medium ◽  
Duration Of Action ◽  
Physico Chemical

Background. A comparative study of the dynamics of iodine desorption from drugs containing iodoform and used after tooth extraction to preserve blood clots and prevention, treatment of inflammatory complications. This took into account the type and form of drugs. The content and desorption of iodine determine the duration of local exposure to the drug on the tissues of the tooth well. Objectives. To study the physico-chemical properties of iodoform containing topical preparations for the prevention and treatment of alveolitis of the jaw. Methods. The objects of the study were complex multicomponent preparations of domestic production, presented in the dental market in the form of gauze bandage, collagen sponge, paste, powder containing iodoform. A standard titrimetric method was used to quantify the iodine content in aqueous systems. For the analysis of changes of iodine content in aqueous model systems applied to the spectrophotometric method in which the concentration of a substance was assessed according to the calibration chart from 0 minutes to 48 hours. In the model solution, the albumin and pH were changed, iodine concentration was determined in 1, 15 and 30 min. Results. Medications significantly differed in both the number of iodoform and desorption in the aquatic environment of the iodine. However, the content of iodoform in the preparations did not exceed the maximum permissible concentration. Desorption of iodine from the bandage after 15 minutes is significantly less than from the viscose flagellum. Desorption of iodine from the collagen sponge remains constant for 24 hours., but increases after 48 hours. Desorption of iodine from the powder is reduced after 45 minutes. Desorption of iodine from the paste gradually increases, reaches a maximum of 105 minutes and persists after 48 hours. In the albumin-bound state, iodine is more easily desorbed in an acidic medium, and at low concentrations of iodine, desorption in a neutral medium is significantly less. Conclusions. The duration of action of iodoform when applied topically affect the dosage form of the carrier (fiber, sponge, paste, powder), the concentration of the drug, the pH and albumin content in the aqueous medium.

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