REARRANGEMENT OF PHENYL CAPRYLATE WITH FERRIC CHLORIDE, TITANIUM TETRACHLORIDE, STANNIC CHLORIDE, AND ZINC CHLORIDE

1942 ◽  
Vol 07 (6) ◽  
pp. 522-527 ◽  
Author(s):  
A. W. RALSTON ◽  
E. W. SEGEBRECHT ◽  
M. R. McCORKLE
Keyword(s):  
Ferric Chloride ◽  
Zinc Chloride ◽  
Titanium Tetrachloride ◽  
Stannic Chloride

Synthesis of o-isopentenylphenols

1971 ◽  
Vol 24 (11) ◽  
pp. 2355 ◽  
Author(s):  
J Hlubucek ◽  
E Ritchie ◽  
WC Taylor
Keyword(s):  
Phosphoric Acid ◽  
Zinc Chloride ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Stannic Chloride ◽  
Counter Ion

The effect of the solvent and the counter-ion on the ring alkylation of 3- and 4-methoxyphenols by isopentenyl bromide has been examined. Under strictly anhydrous conditions good and consistent yields of the o- isopentenylphenols were obtained with the combination potassium- toluene, but sodium-toluene was more convenient. ��� Boron trifluoride etherate was more satisfactory than stannic chloride, zinc chloride, or phosphoric acid in catalysing the condensation of 3- and 4-methoxy-phenols with 2-methylbut-3-en-2-ol to the corresponding o-isopentenylphenols. Aryl α,α-dimethylpropargyl ethers were partially hydrogenated to the corresponding α,α- dimethylallyl ethers which rearranged in boiling N,N-diethyl-aniline to o-isopentenylphenols in high overall yield.

scholarly journals Study of Some Physical and Chemical Properties of Staphylolysin Enzyme purified from Pseudomonas aeruginosa

2014 ◽  
Vol 11 (2) ◽  
pp. 819-828
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Sodium Chloride ◽  
Enzymatic Activity ◽  
Potassium Chloride ◽  
Ferric Chloride ◽  
Zinc Chloride ◽  
Enzyme Stability ◽  
Mercury Chloride ◽  
Initial Activity ◽  
Full Activity

Some of the characters of the Staphylolysin A and D enzymes purified from Pseudomonas aeruginosa P16 and P5 respectively were studied, the molecular weights of Staphylolysin A and D were 20.417 kilo dalton and 23.988 kilo Dalton respectively by SDS- polyacryl amide gel electrophoresis. The optimum pH for staphylolysin A activity was found to be 8 which gives higher activity reaches 150 unit/ml, and for enzyme stability was 7.5-8.5 in which the enzyme nearly retained its full activity, while it was 9.5 for staphylolysin D that gives higher activity of 16 unit/ml,and 8.5-9.5 for enzyme stability in which the enzyme nearly retained its full activity, Maximum activity of two enzymes was obtained at 40C in which the specific activity for staphylolysin A and D were 140 and 16.4 unit/ml, and the two enzymes remained approximately without change at 25-40C for one hour. When the effects of some materials on Staphylolysin A&D activity were studied, the results showed that both sodium chloride & potassium chloride at 1 & 5 mM had the activator effect on enzymatic activity compared with its control where the staphylolysin A and D retained 105% ,108% and 102%, 104% of their activity respectively when treated with sodium chloride, while they retained 110%, 114% and 133%, 118% of their activity respectively when treated with potassium chloride. The enzymatic activity for both enzymes were inhibited when treated with ferric , mercury and zinc chloride at variable ratios, Staphylolysin A kept 73% and 7% of its initial activity respectively when treated with 5mM of ferric chloride and mercury chloride respectively and it kept only 9% of its initial activity when treated with 0.1mM Zinc chloride . Staphylolysin D kept 45% and 13% of it is initial activity respectively when treated with 5mM of ferric chloride and mercury chloride respectively and it kept only 23% of its initial activity when treated with 0.1mM Zinc chloride while enzymatic activity for both enzymes were not affected when treated with EDTA at l0mM and phenyl methyl sulphonyl fluoride (PMSF) at 0.4mM.These results referred to that Staphylolysin A and D are Zn -metallo endopeptidase .

A COMPARISON OF THE PROPERTIES OF PENTAACETATES AND METHYL 1,2-ORTHOACETATES OF GLUCOSE AND MANNOSE

1955 ◽  
Vol 33 (1) ◽  
pp. 109-119 ◽  
Author(s):  
R. U. Lemieux ◽  
Carol Brice
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Zinc Chloride ◽  
Main Product ◽  
Stannic Chloride ◽  
Aqueous Acetic Acid ◽  
Silver Acetate ◽  
Silver Carbonate ◽  
Ethyl Mercaptan ◽  
Glucose Pentaacetate

The rates of exchange of acetate—concurrent with anomerization—between the C1-acetoxy groups of the pentaacetates (0.05 M) of D-glucose and D-mannose and stannic trichloride acetate (0.05 M) in chloroform containing stannic chloride (0.05 M) were determined at 40 °C. using isotopically labelled acetate. 1,2-trans-α-D-Mannose pentaacetate underwent exchange seven times more rapidly than the β-1,2-cis-anomer but eight times less rapidly than 1,2-trans-β-D-glucose pentaacetate. The latter compound was 450 times more reactive than the α-1,2-cis-anomer. In accordance with these results, the D-mannose pentaacetate underwent mercaptolysis in ethyl mercaptan containing zinc chloride at rates intermediate to those found for the D-glucose pentaacetates. The main product from the mannose pentaacetates was in each case ethyl 1,2-trans-α-D-1-thiomannopyranoside tetraacetate (60–70% yield). Tetra-O-acetyl-β-D-glucopyranosyl chloride with silver acetate gave β-D-glucose pentaacetate when the reaction was carried out in dry acetic acid but gave 2,3,4,6-tetra-O-acetyl-α-D-glucose in 90% aqueous acetic acid. Tetra-O-acetyl-β-D-glucopyranosyl chloride with methanol and silver carbonate gave a sirupy product with the properties expected for methyl 1,2-ortho-O-acetyl-α-D-glucopyranose triacetate. The substance was hydrolyzed by 0.005 N hydrochloric acid in 95% dioxane 18 times more rapidly than the corresponding derivative of β-D-mannose. The significance of these observations toward an understanding of the effect of configuration on reactivity is discussed.

Diels–Alder reactions of 2-carbomethoxy-4,4-dimethyl-2-cyclopenten-1-one

1992 ◽  
Vol 70 (5) ◽  
pp. 1545-1554 ◽  
Author(s):  
Hsing-Jang Liu ◽  
Gerardo Ulíbarri ◽  
Eric N. C. Browne
Keyword(s):  
Lewis Acid ◽  
Zinc Chloride ◽  
Thermal Conditions ◽  
Diels Alder ◽  
Stannic Chloride ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Keto Ester ◽  
Thermal Reactions ◽  
High Yields

Diels–Alder additions to keto ester 2 proceed in moderate to high yields with a variety of dienes under selected Lewis acid and thermal conditions. Thermal conditions provide the highest total yields for non-functionalized dienes, but Lewis acid catalysts, particularly stannic chloride, provide highly selective additions in greater net yields. A study of several functionalized dienes shows that zinc chloride is particularly effective in catalyzing additions to 2. No difference in stereoselectivity is observed between zinc chloride and thermal reactions for highly functionalized dienes. The significance of the regiochemical and stereochemical results of the Diels–Alder reactions is discussed.

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