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.

Total synthesis of indole and dihydroindole alkaloids. X.1,2 The preparation of novel oxygenated catharanthine derivatives

1977 ◽  
Vol 55 (18) ◽  
pp. 3227-3234 ◽  
Author(s):  
James P. Kutney ◽  
Gordon H. Bokelman ◽  
Masahiro Ichikawa ◽  
Edwin Jahngen ◽  
Alummoottil V. Joshua ◽  
...  
Keyword(s):  
Double Bond ◽  
Total Synthesis ◽  
Osmium Tetroxide ◽  
Electrophilic Attack ◽  
Naturally Occurring ◽  
Derivatives Of ◽  
Potential Use

Detailed investigations involving the electrophilic attack of various reagents on the 3,4-double bond of catharanthine derivatives (e.g. 3, R = O) furnished a series of novel derivatives of potential use in the syntheses of naturally occurring bisindole alkaloids. These studies include such reagents as peracid, osmium tetroxide, and positive iodine.

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.

scholarly journals Oxazolidinones as Chiral Auxiliaries in the Asymmetric 1,4-Conjugate Addition Reaction Applied to the Total Synthesis of Natural Products: A Supplemental Mini-Review

2018 ◽  
Vol 15 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Vahideh Zadsirjan ◽  
Majid M. Heravi
Keyword(s):  
Total Synthesis ◽  
Biological Activities ◽  
Conjugate Addition ◽  
Chiral Auxiliary ◽  
Addition Reactions ◽  
Chiral Auxiliaries ◽  
Complex Molecules ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Wide Range

Background: The most frequently used chiral auxiliaries, oxazolidinones (Evans' oxazolidinones) have been employed in 1,4-congugate addition reactions to α,β-unsaturated carbonyl compounds. Supplementary to our previous reports in this mini-review, we attempted to underscore the applications of this strategy in a step (steps) in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Objective: In this mini-review, we try to underscore the applications of oxazolidinones (Evans’ oxazolidinones) in 1,4-congugate addition reactions to α,β-unsaturated carbonyl in the total synthesis of some naturally occurring compounds exhibiting diverse biological activities. Conclusion: In spite of well-known superiority of asymmetric catalyzed reactions, the use of auxiliarycontrolled reactions are still considered as commanding, vital and sometimes as only tools in the generation of stereogenic centers during the construction of complex molecules and total synthesis of naturally occurring compounds. The commercial availability, or readily accessibility of a wide variety of chiral amino alcohols as starting materials to synthesize a wide range of oxazolidinones is the merits of them. In addition, the ease of removal and subjection to various and diverse stereoselective reactions make oxazolidinones as the ideal and superior chiral auxiliaries. In this regard, they were successfully used in asymmetric 1,4-conjugate addition reactions with high stereoselectivities. The high degree of asymmetric induction can be attributed to the rigid chelation of N-acyloxazolidinones with metal ions, as well as the covering of one face of the system by the bulkiness of 4-substituent. In summary, in this report, the importance of the applications of chiral oxazolidinones as suitable chiral auxiliaries in the stereoselective, 1,4-conjugate addition reactions in asymmetric synthesis and in particular, the total synthesis of naturally occurring compounds and some complex molecules were underscored. Noticeably, in these total syntheses, this chiral auxiliary is controlling the stereochemistry of a newly created stereogenic center as well as preserving the configuration of other chiral centers, which already have been presented in the precursor. General methods have been established for the attachment of the chiral auxiliary as a moiety to the substrate molecule in high to excellent yields. At the end of these reactions, this auxiliary can be easily removed leaving various desired reactive motifs for the next step in multi-step synthesis.

ChemInform Abstract: Total Synthesis and Determination of the Absolute Configuration of FD-838, a Naturally Occurring Azaspirobicyclic Product.

ChemInform ◽  
2009 ◽  
Vol 40 (47) ◽  
Author(s):  
Yujiro Hayashi ◽  
Kuppusamy Sankar ◽  
Hayato Ishikawa ◽  
Yuriko Nozawa ◽  
Kazutoshi Mizoue ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Absolute Configuration ◽  
Naturally Occurring ◽  
The Absolute
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