A kinetic study of the reductive cleavage of diphenyl ether by sodium in liquid ammonia

1989 ◽  
Vol 54 (1) ◽  
pp. 261-262 ◽  
Author(s):  
Robert R. Dewald ◽  
Nora J. Conlon ◽  
Woo M. Song
Keyword(s):  
Kinetic Study ◽  
Liquid Ammonia ◽  
Diphenyl Ether ◽  
Reductive Cleavage

Benzyl ethers of methyl α-D-glucopyranoside

1980 ◽  
Vol 45 (7) ◽  
pp. 1959-1963 ◽  
Author(s):  
Dušan Joniak ◽  
Božena Košíková ◽  
Ludmila Kosáková
Keyword(s):  
Kinetic Study ◽  
Spectrophotometric Determination ◽  
Reductive Cleavage ◽  
Ether Bond ◽  
Benzyl Ethers ◽  
Acid Catalyzed ◽  
Model Substances ◽  
Hydrolysis Of

Methyl 4-O-(3-methoxy-4-hydroxybenzyl) and methyl 4-O-(3,5-dimethoxy-4-hydroxybenzyl)-α-D-glucopyranoside and their 6-O-isomers were prepared as model substances for the ether lignin-saccharide bond by reductive cleavage of corresponding 4,6-O-benzylidene derivatives. Kinetic study of acid-catalyzed hydrolysis of the compounds prepared was carried out by spectrophotometric determination of the benzyl alcoholic groups set free, after their reaction with quinonemonochloroimide, and it showed the low stability of the p-hydroxybenzyl ether bond.

Reductive cleavage mechanism of diphenyl ether and apparent ipso trapping of an intermediate radical anion with a silyl ether

1982 ◽  
Vol 47 (22) ◽  
pp. 4250-4254 ◽  
Author(s):  
Kundanbhai M. Patel ◽  
Richard J. Baltisberger ◽  
Virgil I. Stenberg ◽  
Neil F. Woolsey
Keyword(s):  
Radical Anion ◽  
Diphenyl Ether ◽  
Reductive Cleavage ◽  
Silyl Ether ◽  
Intermediate Radical

scholarly journals Cleavage of Diphenyl Ether Derivatives by Metallic Sodium in Liquid Ammonia. I

1952 ◽  
Vol 72 (3) ◽  
pp. 384-387 ◽  
Author(s):  
Masao Tomita ◽  
Eiichi Fujita ◽  
Tadashi Abe
Keyword(s):  
Liquid Ammonia ◽  
Diphenyl Ether ◽  
Metallic Sodium

REDUCTIVE CLEAVAGE WITH METAL IN LIQUID AMMONIA: I. THE SELECTIVE CLEAVAGE OF THE BENZYLTHIO C—S BOND VERSUS THE BENZYLIDENEDIOXY C—O BOND IN METHYL S-BENZYL-4,6-O-BENZYLIDENE-2-THIO-α-D-ALTROPYRANOSIDES; THE INFLUENCE OF THE COSOLVENT 1,2-DIMETHOXYETHANE ON THE COURSE OF THE REACTION

1966 ◽  
Vol 44 (5) ◽  
pp. 591-602 ◽  
Author(s):  
U. G. Nayak ◽  
R. K. Brown
Keyword(s):  
Infrared Absorption ◽  
Liquid Ammonia ◽  
Reductive Cleavage ◽  
The Other ◽  
Metallic Sodium ◽  
Absorption Bands ◽  
Strong Band ◽  
The One ◽  
Infrared Absorption Bands ◽  
Phenyl Moiety

The improved solubility of methyl S-benzyl-4,6-O-benzylidene-2-thio-α-D-altropyranoside (1) in liquid ammonia diluted with 1,2-dimethoxyethane has permitted the selective cleavage by metallic sodium or lithium of the C—S bond to give methyl 4,6-O-benzylidene-2-thio-α-D-altropyranoside in 70–75% yield. On the other hand, the slight solubility of I in liquid ammonia alone results only in the completely hydrogenolyzed material, methyl 2-thio-α-D-altropyranoside, along with unchanged I.Generally, in liquid ammonia alone, reductive cleavage is rapid (15–20 min) and the benzylidene and benzyl groups are converted largely into toluene accompanied by a small amount of bibenzyl. In liquid ammonia – 1,2-dimethoxyethane mixtures the reaction is much slower (≥ 1.5 h); under these conditions the benzylidene and benzyl groups are converted to a larger extent into bibenzyl, the rest becoming toluene.The two strong infrared absorption bands (in Nujol) in the region of 766 to 778 cm−1 and 706 to 718 cm−1 have been assigned to the phenyl moiety of the benzylidene group, and the one strong band in the region of 702 cm−1 to the phenyl moiety of the S-benzyl group.

Reductive cleavage with metal in liquid ammonia. II. Olefin formation in attempts at selective cleavage of methyl S-benzyl-4,6-O-benzylidene-3-O-methyl-2-thio-α-d-altropyranoside and its S-methyl analogue by sodium metal in liquid ammonia diluted with 1,2-dimethoxyethane

1967 ◽  
Vol 45 (5) ◽  
pp. 481-494 ◽  
Author(s):  
U. G. Nayak ◽  
M. Sharma ◽  
R. K. Brown
Keyword(s):  
Liquid Ammonia ◽  
Mixed Solvent ◽  
Reductive Cleavage ◽  
Metallic Sodium ◽  
Reaction Conditions ◽  
Sodium Metal ◽  
Alkaline Reaction

When methyl S-benzyl-4,6-O-benzylidene-3-O-methyl-2-thio-α-d-altropyranoside (VI) in liquid ammonia was treated with metallic sodium, a reductive cleavage occurred to give methyl 3-O-methyl-2-thio-α-d-altropyranoside in an 85% yield. In the solvent 1,2-dimethoxy-ethane, the reaction of sodium with VI gave little, if any, reductive cleavage. Instead, a base-catalyzed elimination of methanol took place to give the two olefins methyl,S-benzyl-4,6-O-benzylidene-2,3-didehydro-3-deoxy-2-thio-α-d-erythro-hexopyranoside (IX) and S-benzyl-4,6-O-benzylidene-l,2-didehydro-1-deoxy-3-O-methyl-2-thio-d-ribo-hexopyranose (X). Under the alkaline reaction conditions, IX isomerized partly to a third olefin, methyl.S-benzyl-4,6-O-benzylidene-3,4-didehydro-3-deoxy-2-thio-α-d-erythro(threo)-hexopyranoside (XI).In the mixed solvent liquid ammonia and 1,2-dimethoxyethane, sodium reacted with VI to give a 33% yield of the 2,3-olefin IX. Other products, no doubt present, were not isolated in this experiment.Three analogous olefins were obtained from the reaction of sodium or basic reagents with methyl 4,6-O-benzylidene-3-O,S-dimethyl-2-thio-α-d-altropyranoside (VIa) in 1,2-dimethoxyethane.

Mechanistic and kinetic study on the reaction of 2;4-dibrominated diphenyl ether (BDE-7) with OH radicals

2012 ◽  
Vol 983 ◽  
pp. 31-37 ◽  
Author(s):  
Haijie Cao ◽  
Maoxia He ◽  
Dandan Han ◽  
Yanhui Sun ◽  
Sufang Zhao ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Diphenyl Ether ◽  
Oh Radicals

Reductive cleavage by sodium in liquid ammonia of the lignin of cotton-plant stems

1976 ◽  
Vol 12 (5) ◽  
pp. 574-576
Author(s):  
S. A. Saidalimov ◽  
L. S. Smirnova ◽  
Kh. A. Abduazimov
Keyword(s):  
Cotton Plant ◽  
Liquid Ammonia ◽  
Reductive Cleavage
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