ChemInform Abstract: SYNTHESIS OF O-SUBSTITUTED DERIVATIVES OF 2-(3′,4′-DIHYDROXYPHENYL)INDOLE USING SULFONYL PROTECTIVE GROUPS

1979 ◽  
Vol 10 (2) ◽  
Author(s):  
Y. BAZILE ◽  
P. DE COINTET ◽  
C. PIGEROL
Keyword(s):  
Protective Groups ◽  
Derivatives Of

Aminocyclitols. II. Synthesis of thioanalogues of 2,5-dideoxystreptamine

1978 ◽  
Vol 56 (21) ◽  
pp. 2743-2749 ◽  
Author(s):  
Gerry Kavadias ◽  
Robert Droghini
Keyword(s):  
Thionyl Chloride ◽  
Boron Trifluoride ◽  
Protective Groups ◽  
Thiobenzoic Acid ◽  
Derivatives Of ◽  
L 13

N,N′-Dibenzoyl-2,5-dideoxystreptamine (8b) reacted with thionyl chloride to form the bisoxazoline 9 and the latter compound was treated with thiobenzoic acid to produce the dithiobenzoate 10a. Removal of the protective groups in 10a afforded (l,3/4,6)-4,6-diamino-1,3-cyclohexanedithiol (1) dihydrochloride. Reaction of 8b with triethyl orthoacetate in the presence of boron trifluoride yielded the monooxazoline 12 which, on reaction with thiobenzoic acid followed by deprotection of the resulting 13a, afforded (d,l)-(13/4,6)-4,6-diamino-3-hydroxycyclohexanethiol (2) dihydrochloride. Similarly, 3-N-benzoyl-1-N-ethoxycarbonyl-2,5-dideoxystreptamine (15) and l-N-benzoyl-3-N-ethoxycarbonyl-2,5-dideoxystreptamine (20) were converted via their respective oxazolines 17a and 22a, to the enantiomeric aminothiols 3 and 4. Protected derivatives of 1–4 are also described.

scholarly journals Chemoenzymatic Synthesis and Some Biological Properties of O-phosphoryl Derivatives of (E)-resveratrol

2008 ◽  
Vol 3 (10) ◽  
pp. 1934578X0800301 ◽  
Author(s):  
Danilo Aleo ◽  
Venera Cardile ◽  
Rosa Chillemi ◽  
Giuseppe Granata ◽  
Sebastiano Sciuto
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Binding Affinity ◽  
Spectroscopic Investigation ◽  
Biological Properties ◽  
Chemoenzymatic Synthesis ◽  
Prostate Cancer Cells ◽  
Phosphoramidite Chemistry ◽  
Protective Groups ◽  
Derivatives Of

3- O-, 3,5-di- O- and 4′- O-phosphoryl derivatives of ( E)-resveratrol have been obtained following a chemoenzymatic strategy. Variedly acylated resveratrol derivatives have been obtained first by exploiting regioselective properties of Pseudomonas cepacea or Candida antarctica lipases in organic solvents. Each acyl-resveratrol was then phosphorylated by the phosphoramidite chemistry protocol and in sequence freed of protective groups, affording the desired O-phosphoryl derivative. Following UV-absorption spectroscopic investigation on the interaction of the newly synthesized compounds with DNA, 4′- O-phosphorylresveratrol exhibited the best binding affinity. As a result of cytotoxicity tests, 3- O-phosphorylresveratrol was more active than resveratrol against DU 145 prostate cancer cells.

scholarly journals Synthesis of O-tyrosine Phosphorylated Adducts of Methylphosphonic and Phosphoric Acid Derivatives as Reference Compounds for the Analysis of Biomedical Samples

2019 ◽  
Vol 3 (2) ◽  
pp. 103-110
Author(s):  
Krylov V.I. Rybalchenko I.V.
Keyword(s):  
Atmospheric Pressure ◽  
The Body ◽  
Chemical Weapons ◽  
Amino Groups ◽  
Chemical Agents ◽  
Chemical Weapons Convention ◽  
Toxic Agents ◽  
Protective Groups ◽  
Derivatives Of ◽  
Reference Samples

Organophosphorus chemical agents are included in the 1st List of the Annex on Chemicals of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction (Chemical Weapons Convention, CWC). For the purposes of verification of compliance with the provisions of the CWC, special methods, which are considered the most informative at determining the retrospective effects of organophosphorus toxicants on the body, are necessary. Typical long-lived biomarkers of organophosphate toxic agents are tyrosine phosphorylation products, the presence of which in biomedical samples clearly indicates the exposure to sarin, soman, tabun and V-series agents. We have elaborated methods for the synthesis and isolation of tyrosine adducts derivatives of methylphosphonic and phosphoric acids, used as reference samples. The synthesis scheme included the consecutive protection of carboxyl and amino groups of tyrosine, its O-phosphorylation by the corresponding alkylphosphonates and phosphates, the removal of protective groups with the release of corresponding O-phosphorylated tyrosine adducts. Their purification from im purities was carried out, using column chromatography (SiO2, eluent: dichloromethane/ethyl acetate 1:1). The purity of the obtained products was more than 90 %, so it was possible to involve them in further transformations with the use of catalyst without the threat of its «poisoning». Benzyl and carboxybenzyl protection of phosphorylated L-tyrosines (12–17) was removed by means of catalytic hydrogenation by molecular hydrogen under atmospheric pressure. Target adducts of phosphorylated reagents and L-tyrosin were obtained (63–82 %) in form of crystal white substances, readily soluble in water and ethanol, and poorly – in dichloromethane and acetonitrile

Synthetic Approaches to Unsymmetrically Substituted 5,7-Dihydroxycoumarins

Synthesis ◽  
2020 ◽  
Vol 52 (05) ◽  
pp. 660-672
Author(s):  
Ramil F. Fatykhov ◽  
Oleg N. Chupakhin ◽  
Anna K. Inyutina ◽  
Igor A. Khalymbadzha
Keyword(s):  
Total Synthesis ◽  
Drug Candidates ◽  
The Past ◽  
Factors Influencing ◽  
Subsequent Separation ◽  
Protective Groups ◽  
Separation Of Mixtures ◽  
Synthetic Approaches ◽  
Hydroxy Groups ◽  
Derivatives Of

The chemical equivalence of the hydroxy groups in the 5,7-dihydroxycoumarin core has challenged synthetic chemists to develop short and efficient strategies for the selective modification of one of the hydroxy groups leaving the second intact. Over the past 100 years, chemists have proposed various approaches to distinguishing between these two groups according to their reactivity. While the early syntheses included simple nonselective reactions of both hydroxy groups and the subsequent separation of mixtures of the 5-O- and 7-O-isomers formed, recent sophisticated approaches often include the introduction of protective groups for selective directing reactions or the completely controlled construction of the 5,7-dihydroxycoumarin framework by Horner–Wadsworth–Emmons reaction. This review discusses in detail approaches towards unsymmetrically substituted 5,7-dihydroxycoumarins as well as factors influencing 5-O vs. 7-O regioselectivity of reactions of 5,7-dihydroxycoumarins. This review covers all the literature since 1921 with an emphasis on recent works. This critical review may facilitate the synthesis of new drug candidates as well as the total synthesis of natural products.1 Introduction2 O-Modification of 5,7-Dihydroxycoumarins2.1 Alkylation/Alkenylation2.2 Acylation2.3 Sulfonylation2.4 Silylation2.5 Acylation Followed by Alkylation3 Other Approaches3.1 Synthesis from Substituted Phloroglucinol3.2 Synthesis from Derivatives of 2-Acylphloroglucinol4 Conclusion

Physical Properties of TCNQ Salts with N-Methyl Derivatives of Pyridine

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik
Keyword(s):  
Physical Properties ◽  
Methyl Derivatives ◽  
Derivatives Of
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