Phosphonolipids. XV. Synthesis of a dihydroceramide aminoethylphosphonate

1968 ◽  
Vol 46 (3) ◽  
pp. 525-532 ◽  
Author(s):  
Erich Baer ◽  
Bimal C. Pal
Keyword(s):  
Chemical Synthesis ◽  
Acid Chloride ◽  
Phosphonic Acid ◽  
Steam Distillation ◽  
Free Acid ◽  
Reaction Products ◽  
New Class ◽  
Naturally Occurring ◽  
Benzoyl Group ◽  
Complex Lipids

The first chemical synthesis of a dihydroceramide aminoethylphosphonate is described. It is a saturated representative of a new class of recently discovered, naturally occurring complex lipids derived from phosphonic acid. The compound, viz. erythro-N-palmitoyl-DL-dihydrosphingosyl-1-(2-aminoethyl)-phosphonate, was obtained by two procedures: phosphonylation of erythro-N-palmitoyl-3-O-benzoyl-DL-dihydrosphingosine with (2-N,N-dibenzylammoethyl)phosphonic acid chloride (hydrochloride) and triethylamine, or with (2-phthalimidoethyl)phosphonic acid monochloride and triethylamine, and freeing the reaction products of both procedures, viz. erythro-N-palmitoyl-3-O-benzoyl-DL-dihydrosphingosyl-1-(2-N,N-dibenzylaminoethyl)phosphonate and erythro-N-palmitoyl-3-O-benzoyl-DL-dihydrosphingosyl-1-(2-phthalimidoethyl)phosphonate, from their protective benzyl or phthaloyl group by hydrogenolysis or hydrazinolysis, respectively, followed in both cases by removal of the benzoyl group by saponification.The (2-N,N-dibenzylaminoethyl)phosphonic acid was obtained by treating (2-bromoethyl)phosphonic acid with N,N-dibenzylamine and converting the reaction product, viz. the dibenzylammonium salt of (2-N,N-dibenzylaminoethyl)phosphonic acid, into the free acid by steam distillation.

Phosphonolipids. XXVII. Synthesis of O-(2-Aminoethyl)phosphono-L-serine and its Stereoisomer

1974 ◽  
Vol 52 (8) ◽  
pp. 718-722 ◽  
Author(s):  
Erich Baer ◽  
Jeno T. Eber
Keyword(s):  
Sulfuric Acid ◽  
Phosphonic Acid ◽  
Benzyl Ester ◽  
Palladium Black ◽  
Simultaneous Removal ◽  
Reaction Products ◽  
Naturally Occurring ◽  
Phosphate Diester ◽  
Serine Phosphate

The synthesis of O-(2-aminoethyl)phosphono-L-serine and O-(2-aminoethyl)phosphono-D-serine is described. The phosphonic acid analogues were obtained by the reaction of O-(2-N,N-dibenzylaminoethyl)phosphonic acid monochloride and triethylamine with N-carbobenzoxy-L-serine benzyl ester and N-carbobenzoxy-D-serine benzyl ester, respectively, followed by the simultaneous removal of the protective carbobenzoxy- and benzyl groups of the reaction products, i.e. O-(2-N,N-dibenzylaminoethyl)phosphono-N-carbobenzoxy-L-serine benzyl ester and its stereoisomer, by hydrogenolysis in 95% ethanol with palladium black catalyst in the presence of sulfuric acid. The O-(2-aminoethyl)phosphono-L-serine and its stereoisomer were obtained in overall yields of about 40% of theory. They are phosphonic acid analogues of the naturally occurring O-(ethanolamine)-O-(L-serine)phosphate diester and its stereoisomer, respectively.

Phosphonolipids. XX. Total synthesis of a naturally occurring ceramide aminoethylphosphonate and of its enantiomer

1969 ◽  
Vol 47 (6) ◽  
pp. 603-610 ◽  
Author(s):  
Erich Baer ◽  
G. Raghltpati Sarma
Keyword(s):  
Total Synthesis ◽  
Acid Chloride ◽  
Phosphonic Acid ◽  
Alkaline Hydrolysis ◽  
Naturally Occurring ◽  
Analogous Manner ◽  
Derivatives Of

The first synthesis of a naturally occurring C18-ceramide aminoethylphosphonate is described. The erythro-N-palmitoyl-D-sphingosyl-1-(2-aminoethyl)phosphonate was obtained by phosphonylation of erythro-N-palmitoyl-3-0-benzoyl-D-sphingosine with (2-phthalimidoethyl)phosphonic acid chloride and triethylamine, and consecutive removal of the protective phthaloyl and benzoyl groups of the reaction product, erythro-N-palmitoyl-3-0-benzoyl-D-sphingosyl-1-(2-phthalimidoethyl)phosphonate, by hydrazinolysis and mild alkaline hydrolysis, respectively. The unnatural l isomer was prepared in an analogous manner from erythro-N-palmitoyl-3-0-benzoyl-L-sphingosine. Comparison of the synthetic and natural ceramide aminoethylphosphonates confirmed the structure tentatively assigned by Rouser, Hori, and Hayashi and their colleagues to the C18-ceramide aminoethylphosphonates of a variety of shellfish, snails, and cephalopods, and established the fact that the natural ceramide aminoethylphosphonates are derivatives of D-sphingosine.

Phosphonolipids. XXVI. Mixed-Acid Phosphonocephalins: Synthesis of α′-Stearoyl- β-oleoyl-L-α-glyceryl-(2-aminoethyl)phosphonate

1974 ◽  
Vol 52 (7) ◽  
pp. 570-574 ◽  
Author(s):  
Erich Baer
Keyword(s):  
Fatty Acid ◽  
Phosphonic Acid ◽  
Glycerol Moiety ◽  
Mixed Acid ◽  
New Class ◽  
Naturally Occurring ◽  
Acid Analogue

The synthesis of α′-stearoyl-β-oleoyl-L-α-glyceryl-(2-aminoethyl)phosphonate is reported. It is a member of a new class of phosphonolipids containing two dissimilar fatty acid substituents, one of which is unsaturated and occupies the 2 or β position of the glycerol moiety. The mixed-acid phosphonolipid, a phosphonic acid analogue of naturally occurring L-(α-stearoyl-β-oleoyl)cephalin, was obtained by phosphonylating D-α-stearoyl-β-oleoylglycerol with (2-phthalimidoethyl) phosphonic acid monochloride and triethylamine, and freeing the resulting α-stearoyl-β-oleoyl-L-α-glyceryl-(2-phthalirnidoethyl)phosphonate of its protective phthaloyl group by hydrazinolysis.

2,2-Dialkylacetic Acids -A New Class of Naturally Occurring Lipid Constituents

1995 ◽  
Vol 50 (1-2) ◽  
pp. 123-126 ◽  
Author(s):  
Gottfried Raab ◽  
Jürgen Jacob
Keyword(s):  
Retention Time ◽  
Relative Retention Time ◽  
Methyl Esters ◽  
South American ◽  
Time Data ◽  
New Class ◽  
The Past ◽  
Relative Retention ◽  
Naturally Occurring ◽  
Acetic Acids

Abstract The uropygial gland waxes of the South American red-legged Seriema (Cariama cristata (L., 1766)) were found to be composed of unbranched alcohols and 2,2′-dialkyl-substituted acetic acids which so far have not been found in skin lipids. When used as a chemosystematic character, the occurrence of this lipid class separates the order Cariamiformes (Seriemas) from all other avian orders hitherto investigated, especially from the Gruiformes (cranes and rails) to which they have been tentatively attributed in the past. From the GC retention time data now available for a series of 2-alkyl-substituted fatty acid methyl esters relative retention time indices for other compounds may be predicted.

scholarly journals C–H-Functionalization logic guides the synthesis of a carbacyclopamine analog

2014 ◽  
Vol 10 ◽  
pp. 1564-1569 ◽  
Author(s):  
Sebastian Rabe ◽  
Johann Moschner ◽  
Marina Bantzi ◽  
Philipp Heretsch ◽  
Athanassios Giannis
Keyword(s):  
Chemical Synthesis ◽  
New Class ◽  
Metal Catalyzed ◽  
Acid Stable

The chemical synthesis of carbacyclopamine analog 2, a cyclopamine analog with an all-carbon E-ring, is reported. The use of C–H-functionalization logic and further metal-catalyzed transformations allows for a concise entry to this new class of acid-stable cyclopamine analogs.

scholarly journals An Expeditious Total Synthesis of 5′-Deoxy-toyocamycin and 5′-Deoxysangivamycin

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 737 ◽  
Author(s):  
Xiangyou Dong ◽  
Jie Tang ◽  
Chen Hu ◽  
Jiang Bai ◽  
Haixin Ding ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Benzoyl Group

In present paper, an expeditious total synthesis of naturally occurring 5′-deoxytoyocamycin and 5′-deoxysangivamycin was accomplished. Because of the introduction of a benzoyl group at N-6 of 4-amino-5-cyano-6-bromo-pyrrolo[2,3-d]pyrimidine, a Vorbrüggen glycosylation with 1,2,3-tri-O-acetyl-5-deoxy-β-D-ribofuranose afforded a completely regioselective N-9 glycosylation product, which is unambiguously confirmed by X-ray diffraction analysis. All of the involved intermediates were well characterized by various spectra.

LINOLEIC ACID AND ITS ISOMERS

1938 ◽  
Vol 16b (5) ◽  
pp. 158-175 ◽  
Author(s):  
J. W. McCutcheon
Keyword(s):  
Linoleic Acid ◽  
Melting Point ◽  
Sunflower Seed ◽  
Seed Oil ◽  
Additional Data ◽  
Free Acid ◽  
Optically Active ◽  
Naturally Occurring ◽  
Tetrabromostearic Acid ◽  
Asymmetric Carbon

Linoleic acid has been prepared from sunflower seed oil by a modification of Rollett's method. The melting point of the solid tetrabromostearic acid is placed at 115.2 °C. The boiling point, specific gravity, iodine value, and refractive index of the ethyl ester and the melting point of the free acid were determined. Linoleamide was prepared, and its melting point is placed at approximately 58 °C. Through rebromination of the prepared linoleic acid, the isomeric liquid tetrabromostearic acid was isolated, and is described. Its reduced acid is shown to be identical with that derived from the solid isomer. From these data and additional data from the literature, it was concluded that bromination and debromination cause no cis-trans isomerization, and that the two pairs of optically active enantiomorphous bromo derivatives exist, not because of their derivation from different acids, but rather because of the four asymmetric carbon atoms which they contain. Therefore, only one naturally occurring linoleic acid is at present known which is identical with that produced through reduction of the tetrabromide that melts at 115.2 °C. or the corresponding liquid derivative. No attempt is made to assign any particular cis-trans configuration to this acid, or to exclude the theoretical existence of three others.

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