Studies of dialkyl ether phospholipids. I. Chemical synthesis of some model compounds

1970 ◽  
Vol 48 (5) ◽  
pp. 585-593 ◽  
Author(s):  
Jung-Shou Chen ◽  
Peter G. Barton
Keyword(s):  
Chemical Synthesis ◽  
Free Product ◽  
Methyl Iodide ◽  
Cadmium Chloride ◽  
Chloride Complex ◽  
Protecting Group ◽  
Subsequent Reaction ◽  
Model Compounds ◽  
Ether Phospholipids ◽  
Catalytic Hydrogenolysis

The syntheses of three 1,2-dialkyl-sn-glycero-3-phosphates and one new 1,2-dialkyl-sn-glycerol are described. 1,2-Dioctadecyl-sn-glycero-3-phosphate was obtained by phosphorylation of 1,2-dioctadecyl-sn-glycerol with diphenylphosphorodichloridate and subsequent catalytic hydrogenolysis. 1,2-Dioctadecyl-sn-glycero-3-(methyl)phosphorylcholine was prepared by phosphorylation of the same dialkyl glycerol with methylphosphorodichloridate and subsequent reaction with choline iodide. 1,2-Dimethyl-sn-glycerol was prepared by treatment of 3-benzyl-sn-glycerol with methyl iodide and KOH followed by hydrogenolysis to remove the protecting group. This compound was then phosphorylated with phenylphosphorodichloridate, the product allowed to react with choline iodide, and the iodide-free product hydrogenated catalytically to yield 1,2-dimethyl-sn-glycero-3-phosphorylcholine which was characterized as the cadmium chloride complex. Some improvements in an established synthesis of 1,2-dioctadecyl-sn-glycerol are described.

The synthesis of a carbohydrate-like dihydrooxazine and tetrahydrooxazine as putative inhibitors of glycoside hydrolases: A direct synthesis of isofagomine

2002 ◽  
Vol 80 (8) ◽  
pp. 857-865 ◽  
Author(s):  
Wayne M Best ◽  
James M Macdonald ◽  
Brian W Skelton ◽  
Robert V Stick ◽  
D Matthew G Tilbrook ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Glycoside Hydrolases ◽  
Crystalline Solid ◽  
Glycosidase Inhibitors ◽  
Protecting Group ◽  
Mild Acid Hydrolysis ◽  
Catalytic Hydrogenolysis ◽  
Palladium On Carbon ◽  
Mild Acid

The treatment of benzyl 2,3-O-isopropylidene-β-L-xylopyranoside with N-hydroxyphthalimide under Mitsunobu conditions, followed by protecting-group interchange, gave benzyl 4-O-[(tert-butoxycarbonyl)amino]-2,3- O-isopropylidene-α-D-arabinoside. Mild acid hydrolysis and catalytic hydrogenolysis afforded 4-O-[(tert-butoxycarbonyl)amino]-D-arabinose that, upon heating in water, gave the dihydrooxazine [(4R,5S,6R)-5,6-dihydro-4,5-dihydroxy-6-hydroxymethyl-4H-1,2-oxazine] as a crystalline solid. A single-crystal structure determination of this solid showed it to exist in the 5H6 conformation. Reduction of the dihydrooxazine gave the tetrahydrooxazine [(4R,5S,6R)-4,5-dihydroxy-6-hydroxymethyl-3,4,5,6-tetrahydro-2H-1,2-oxazine]. The dihydrooxazine was an effective inhibitor of two β-glucosidases (Ki = 27 and 35 µM). Benzyl 2,3-O-isopropylidene-β-L-xylopyranoside, via the derived imidazylate, was converted into a nitrile that, upon reduction and protecting-group manipulations, gave benzyl 4-C-aminomethyl-4-deoxy-α-D-arabinoside. Treatment of this amine with hydrogen and palladium-on-carbon gave isofagomine.Key words: dihydrooxazine, tetrahydrooxazine, isofagomine, iminosugars, glycosidase inhibitors.

Bimetallic effects in the catalytic hydrogenolysis of lignin and its model compounds on Nickel-Ruthenium catalysts

2019 ◽  
Vol 194 ◽  
pp. 106126 ◽  
Author(s):  
Chen Zhu ◽  
Jing-Pei Cao ◽  
Xiao-Yan Zhao ◽  
Tao Xie ◽  
Ming Zhao ◽  
...  
Keyword(s):  
Ruthenium Catalysts ◽  
Model Compounds ◽  
Catalytic Hydrogenolysis

scholarly journals Chemical synthesis of the pentasaccharide repeating unit of the O-specific polysaccharide from Escherichia coli O132 in the form of its 2-aminoethyl glycoside

2019 ◽  
Vol 15 ◽  
pp. 2563-2568
Author(s):  
Debasish Pal ◽  
Balaram Mukhopadhyay
Keyword(s):  
Escherichia Coli ◽  
Chemical Synthesis ◽  
Building Blocks ◽  
Protecting Group ◽  
E Coli ◽  
Specific Polysaccharide

The total chemical synthesis of the pentasaccharide repeating unit of the O-polysaccharide from E. coli O132 is accomplished in the form of its 2-aminoethyl glycoside. The 2-aminoethyl glycoside is particularly important as it allows further glycoconjugate formation utilizing the terminal amine without affecting the stereochemistry of the reducing end. The target was achieved through a [3 + 2] strategy where the required monosaccharide building blocks are prepared from commercially available sugars through rational protecting group manipulation. The NIS-mediated activation of thioglycosides was used extensively for the glycosylation reactions throughout.

scholarly journals Chemical Synthesis of Two Series of Nerve Agent Model Compounds and Their Stereoselective Interaction with Human Acetylcholinesterase and Human Butyrylcholinesterase

2009 ◽  
Vol 22 (10) ◽  
pp. 1669-1679 ◽  
Author(s):  
Nora H. Barakat ◽  
Xueying Zheng ◽  
Cynthia B. Gilley ◽  
Mary MacDonald ◽  
Karl Okolotowicz ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Nerve Agent ◽  
Model Compounds ◽  
Agent Model ◽  
Human Butyrylcholinesterase

Synthesis of Diphytanyl Ether Analogues of Phosphatidic Acid and Cytidine Diphosphate Diglyceride

1971 ◽  
Vol 49 (3) ◽  
pp. 275-281 ◽  
Author(s):  
M. Kates ◽  
C. E. Park ◽  
B. Palameta ◽  
C. N. Joo
Keyword(s):  
Chemical Synthesis ◽  
Phosphatidic Acid ◽  
Physical Properties ◽  
Acid Hydrolysis ◽  
Anhydrous Benzene ◽  
Catalytic Hydrogenolysis ◽  
Cytidine Monophosphate ◽  
Cytidine Diphosphate

The chemical synthesis of 2,3-di-O-phytanyl-sn-1-glycerophosphate was carried out in two ways: (a) by phosphorylation of 2,3-diphytanyl-sn-glycerol with diphenylphosphoryl chloride in pyridine, followed by catalytic hydrogenolysis of the phenyl groups; and (b) by condensation of 1-iodo-2,3-di-O-phytanyl-sn-glycerol with silver di-p-nitrobenzyl phosphate in anhydrous benzene, followed by catalytic hydrogenolysis of the p-nitrobenzyl groups. The free diether phosphatidic acid obtained was converted to the dipotassium and disodium salts. The diether phosphatidic acid was also converted to the diether analogue of cytidine diphosphate diglyceride by condensation with cytidine monophosphate morpholidate in pyridine. The physical properties of these diether analogues are described, as well as their stabilities towards acid hydrolysis.

THE PREPARATION OF L-α-GLYCERYLPHOSPHORYLCHOLINE FROM LECITHINS

1955 ◽  
Vol 33 (5) ◽  
pp. 761-766 ◽  
Author(s):  
N. H. Tattrie ◽  
C. S. McArthur
Keyword(s):  
Cadmium Chloride ◽  
Inorganic Salt ◽  
Optical Rotation ◽  
Chloride Complex ◽  
Ion Exchange Resins ◽  
Aqueous Alcohol ◽  
Synthetic Compound ◽  
Exchange Resins ◽  
Hydrolysis Of ◽  
Crude Lecithin

Investigation of the hydrolysis of phosphatidylcholines (lecithins) in hot aqueous alcohol under the influence of mercuric chloride has shown that glycerylphosphorylcholine is formed and that neither racemization nor migration of the phosphorylcholine moiety occurs. The fatty acids are split off much more rapidly than is choline and as a consequence appreciable amounts of glycerylphosphorylcholine are formed. On the basis of these observations a procedure was devised for the hydrolysis of crude lecithin and the isolation of glycerylphosphorylcholine in a yield of 69%. The product was identified as L-α-glycerylphosphorylcholine by analysis of its cadmium chloride complex, and comparison of its optical rotation with that of the synthetic compound of known configuration. Recovery of the diester from this complex was accomplished through removal of the inorganic salt by ion-exchange resins and the free L-α-glycerylphosphorylcholine was crystallized from 99% ethanol.

Flavonoid intermediates for the synthesis of mopanol trimethyl ether[trans-trans-7,7',8'-Trimethoxyisochromano(4',3':2,3)chroman-4-ol]

1976 ◽  
Vol 29 (1) ◽  
pp. 191 ◽  
Author(s):  
JW Clark-Lewis ◽  
DP Cox
Keyword(s):  
Carboxylic Acid ◽  
Potassium Carbonate ◽  
Dimethyl Sulphate ◽  
Metal Hydrides ◽  
Cyclic Ether ◽  
Protecting Group ◽  
Model Compounds ◽  
Initial Product ◽  
Dibenzyl Ether ◽  
Trimethyl Ether

Preparation of a number of intermediates for the synthesis of (�)-mopanol trimethyl ether is described, together with exploratory reactions with model compounds, and especially with 7-methoxyflavanone-2'-carboxylic acid. 7-Methoxyflavan-4-ol, the initial product from reduction of 7-methoxyflavanone-2'-carboxylic acid with complex metal hydrides, was found to undergo facile dehydration to a novel intramolecular dibenzyl ether [the cyclic ether (19)*]. It was noted that the methoxymethyl group, which may be used as a protecting group for phenols, did not survive the conditions of methylation with dimethyl sulphate and potassium carbonate in acetone.

scholarly journals The 9-Fluorenylmethoxycarbonyl (Fmoc) Group in Chemical Peptide Synthesis – Its Past, Present, and Future

2020 ◽  
Vol 73 (4) ◽  
pp. 271 ◽  
Author(s):  
Wenyi Li ◽  
Neil M. O'Brien-Simpson ◽  
Mohammed Akhter Hossain ◽  
John D. Wade
Keyword(s):  
Chemical Synthesis ◽  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Peptide Bond ◽  
Synthesis Methods ◽  
Protecting Group ◽  
Fmoc Group ◽  
The 1960S ◽  
The Many

The chemical formation of the peptide bond has long fascinated and challenged organic chemists. It requires not only the activation of the carboxyl group of an amino acid but also the protection of the Nα-amino group. The more than a century of continuous development of ever-improved protecting group chemistry has been married to dramatic advances in the chemical synthesis of peptides that, itself, was substantially enhanced by the development of solid-phase peptide synthesis by R. B. Merrifield in the 1960s. While the latter technology has continued to undergo further refinement and improvement in both its chemistry and automation, the development of the base-labile 9-fluorenylmethoxycarbonyl (Fmoc) group and its integration into current synthesis methods is considered a major landmark in the history of the chemical synthesis of peptides. The many beneficial attributes of the Fmoc group, which have yet to be surpassed by any other Nα-protecting group, allow very rapid and highly efficient synthesis of peptides, including ones of significant size and complexity, making it an even more valuable resource for research in the post-genomic world. This review charts the development and use of this Nα-protecting group and its adaptation to address the need for more green chemical peptide synthesis processes.

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