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Piet Herdewijn - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Poly(ADP‐ribose) Monomer Containing 2′‐O‐α‐D‐Ribofuranosyl Adenosine
Current protocols in human genetics, 2019Co-Authors: Sergey N. Mikhailov, Mikhail S. Drenichev, Vladimir E. Oslovsky, Irina V. Kulikova, Piet HerdewijnAbstract:In this article, the earlier reported procedure for the synthesis of 2'-O-β-D-ribofuranosyl nucleosides was extended to the synthesis of 2'-O-α-D-ribofuranosyl adenosine, a monomeric unit of poly(ADP-ribose). It consists in condensation of a small excess of 1-O-acetyl-2,3,5-tri-O-benzoyl-α,β-D-arabinofuranose activated with tin tetrachloride with 3',5'-O-tetra-isopropyldisiloxane-1,3-diyl-ribonucleosides in 1,2-dichloroethane. The following Debenzoylation and silylation of arabinofuranosyl residue and inversion of configuration at C-2'' atom of arabinofuranosyl residue and final removal of silyl protective groups gave 2'-O-α-D-ribofuranosyl adenosine in overall 13% to 21% yield. © 2019 by John Wiley & Sons, Inc.
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regioselective 2 o Debenzoylation of 2 3 di o benzoyl threose nucleosides
Tetrahedron Letters, 2013Co-Authors: Miyeon Jang, Matheus Froeyen, Piet HerdewijnAbstract:Abstract A simple and convenient procedure for the regioselective 2′-O-Debenzoylation of 2',3'-di-O-benzoyl threose nucleosides has been achieved successfully affording 3′-O-benzoyl threose nucleosides, which are useful starting material synthons for the synthesis of modified threose nucleosides for different purposes.
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Regioselective 2′-O-Debenzoylation of 2',3'-di-O-benzoyl threose nucleosides
Tetrahedron Letters, 2013Co-Authors: Miyeon Jang, Matheus Froeyen, Piet HerdewijnAbstract:Abstract A simple and convenient procedure for the regioselective 2′-O-Debenzoylation of 2',3'-di-O-benzoyl threose nucleosides has been achieved successfully affording 3′-O-benzoyl threose nucleosides, which are useful starting material synthons for the synthesis of modified threose nucleosides for different purposes.
Antonín Holý - One of the best experts on this subject based on the ideXlab platform.
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New carbocyclic nucleoside analogues built on a bicyclo[2.2.2]octane-2,2-dimethanol template
Collection of Czechoslovak Chemical Communications, 2009Co-Authors: Hubert Hřebabecký, Martin Dračínský, Antonín HolýAbstract:(1 R *,4 S *,6 S *)-6-(6-Chloro-9 H -purin-9-yl)bicyclo[2.2.2]octane-2,2-dimethanol ( 22 ) and (1 R *,4 R *,5 S *)-5-(6-chloro-9 H -purin-9-yl)bicyclo[2.2.2]octane-2,2-dimethanol ( 17 ) were prepared from (1 R *,4 R *)-bicyclo[2.2.2]oct-5-ene-2,2-dimethanediyl dibenzoate ( 7 ) using two approaches. The first procedure consists in hydroboration of 7 , separation of obtained 6- exo -hydroxy derivative 8 and 5- exo -hydroxy derivative 9 , conversion of 8 and 9 to endo -hydroxy derivatives 12 and 13 , respectively, and the Mitsunobu reaction with 6-chloropurine. Only 5-(6-chloropurinyl) analogue 16 was obtained in an acceptable yield. The target analog 17 was prepared by reductive Debenzoylation of 16 . The further reactions were hydroboration of 7 , treatment with hydroxylamine- O -sulfonic acid and Debenzoylation. Chloropurine analogues 17 and 22 were built on the obtained 6- exo -amino- and 5- exo -aminobicyclo[2.2.2]octane-2,2-dimethanols 18 and 19 , respectively. Compounds 17 and 22 were converted to adenine ( 23 , 24 ) and 6-(cyclopropylamino)purine analogues ( 25 , 26 ).
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Synthesis of 1-(3-Azido-2,3-dideoxy-4- C -hydroxymethyl-α-L- threo -pentofuranosyl)thymine, 1-(2,3-Dideoxy-4- C -hydroxymethyl-α-L- glycero -pentofuranosyl)thymine and 1-(2,3-Dideoxy-4- C -hydroxymethyl-α-L- glycero -pent-2-enofuranosyl)thymine
Collection of Czechoslovak Chemical Communications, 1993Co-Authors: Hubert Hřebabecký, Antonín HolýAbstract:1-(2- O -Acetyl-3,5-di- O -benzoyl-4- C -benzoyloxymethyl-α-L-arabinofuranosyl)thymine ( II ) was converted to 2,2'-anhydro derivative V by selective deacetylation, mesylation and treatment with 1,8-diazabicyclo[5.4.0]undec-7-ene. Cleavage of 2,2'-anhydro ring in compound V with hydrogen chloride or bromide afforded the respective 2'-chloro and 2'-bromo derivatives VI and VII . Reaction of compound VII with Cu/Zn couple and subsequent Debenzoylation led to 1-(2,3-dideoxy-4- C -hydroxymethyl-α-L-pent-2-enofuranosyl)thymine ( IX ). Catalytic hydrogenation of IX gave 1-(2,3-dideoxy-4- C -hydroxymethyl-α-L- glycero -pentofuranosyl)thymine ( X ). Dehalogenation of compound VI with tributyltin hydride and Debenzoylation afforded 1-(2-deoxy-4- C -hydroxymethyl-α-L- erythro -pentofuranosyl)thymine ( XII ). Tritylation of compound XII , followed by mesylation, detritylation and nucleophilic substitution with azide furnished 1-(3-azido-2,3-dideoxy-4- C -hydroxymethyl-α-L- threo -pentofuranosyl)thymine ( XXII ).
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Synthesis of 1-(3-azido-2,3-dideoxy-β-d-allofuranosyl)thymine, 1-(2,3-dideoxy-β-d-allofuranosyl)thymine, and 1-(2,3-dideoxy-β-d-erythro-hex-2-enofuranosyl)thymine
Carbohydrate Research, 1991Co-Authors: Hubert Hřebabecký, Antonín HolýAbstract:Abstract 1-(2-O-Acetyl-3,5,6-tri-O-benzoyl-β- d -glucofuranosyl)thymine (1) was converted into the 2,2′-anhydro derivative 4 by selective deacetylation, mesylation, and treatment with 1,8-diazabicyclo[5.4.0]undec-7-ene. Cleavage of the 2,2′-anhydro ring in 4 with hydrogen bromide or hydrogen chloride led to the 2′-bromo (5) or 2′-chloro (6) derivative, respectively. Dehalogenation of 6 with tributylstannane and then Debenzoylation gave 1-(2-deoxy-β- d -arabino-hexofuranosyl)thymine (8). Isopropylidenation of 8 followed by mesylation, azide displacement, and deprotection gave 1-(3-azido-2,3-dideoxy-β- d -ribo-hexofuranosyl)-thymine (12). Oxidation of 12 with Dowex 1 (IO4−) resin followed by reduction with Dowex 1 (BH4−) resin gave 1-(3-azido-2,3-dideoxy-β- d -erythro-pentofuranosyl)thymine (AZT). Catalytic hydrogenation of 5 afforded a mixture of 1-(5,6-di-O-benzoyl-2,3-dideoxy-β- d -erythro-hexofuranosyl)thymine (13) and 1-(3,5,6-tri-O-benzoyl-2-deoxy- β- d -arabino-hexofuranosyl)thymine (7). Reaction of 5 with a Cu/Zn couple gave 1-(5,6-di-O-benzoyl-2,3-dideoxy-β- d -erythro-hex-2-enofuranosyl)thymine (15). 1-(2,3-Dideoxy-β- d - erythro-hexofuranosyl)thymine (14) and 1-(2,3-dideoxy-β- d -erythro-hex-2-enofuranosyl)thymine (16) were obtained by Debenzoylation.
Kanchugarakoppal S. Rangappa - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of model ultimate carcinogens/metabolites derived from lead tetraacetate oxidation of arylnitrones: 2 `-deoxyguanosine adducts
Synthesis, 2004Co-Authors: H. Mallesha, K. R. Ravikumar, K. Mantelingu, Kanchugarakoppal S. RangappaAbstract:The synthesis of model reactive metabolites 4a-c by lead tetraacetate (LTA) oxidation of arylnitrones 3a-c is described. Compounds 4a-c react with deoxyguanosine (dG) to give N-benzoylated C8-adducts 5a-c. Following Debenzoylation with the heterogeneous system (sodium carbonate/methanol) leads to the corresponding C8-adducts 6a-c.
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Synthesis of N-acetoxy-N-benzoyl-2-aminofluorene, an ultimate carcinogen by LTA oxidation of alpha-phenyl-N-(2-aminofluorenyl)nitrone, and N-(2 `-deoxyguanosin-8-yl)-2-aminofluorene
Synthesis, 2004Co-Authors: H. Mallesha, K. R. Ravi Kumar, Kanchugarakoppal S. RangappaAbstract:The rearrangement of a new alpha -phenyl-N-(2-aminofluorenyl)nitrone (8) to a new ultimate carcinogen, N-acetoxy-N-benzoyl-2-aminofluorene (9) is achieved in a lead tetraacetate (LTA) oxidation reaction. Compound 9 reacts with deoxyguanosine (dG) at pH 7.0 to give N-(benzoyl)-N-(deoxyguanosin-8-yl)-2-aminofluorene (10). Subsequent Debenzoylation with the heterogeneous system (sodium carbonate/methanol) leads to the C8-adduct, N-(2'-deoxyguanosin-8-yl)-2-aminofluorene (11).
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Synthesis and characterization of nucleoside derivatives, n-(benzoyl)-n-(deoxyguanosin-8-yl)4-aminobiphenyl and n-(2'-deoxyguanosin-8-yl)4-aminobiphenyl via alpha-phenyl-n-(4-biphenyl)nitrone.
Nucleosides Nucleotides & Nucleic Acids, 2002Co-Authors: H. Mallesha, K. R. Ravi Kumar, Kanchugarakoppal S. RangappaAbstract:ABSTRACT Lead tetraacetate (LTA) oxidation of α-Phenyl-N-(4-biphenyl)nitrone (8) to give a new ultimate carcinogen, N-acetoxy-N-benzoyl-4-aminobiphenyl (9) which was reacted with deoxyguanosine (dG) at pH 6.9 to give nucleoside derivative, N-(benzoyl)-N-(deoxyguanosin-8-yl)-4-aminobiphenyl (10). Following Debenzoylation with sodium carbonate-methanol leads to N-(2′-deoxyguanosin-8-yl)-4-aminobiphenyl (11).
Gary R. Gray - One of the best experts on this subject based on the ideXlab platform.
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Authentic standards for the reductive-cleavage method: the positional isomers of partially methylated and acetylated or benzoylated 1,5-anhydro-L-arabinitol.
Carbohydrate research, 1998Co-Authors: Larry E. Elvebak, P Mcnally, Gary R. GrayAbstract:Described herein is the synthesis of the eight positional isomers of methylated and acetylated or benzoylated 1,5-anhydro-L-arabinitol. The compounds were generated simultaneously from 1,5-anhydro-L-arabinitol by sequential partial methylation and benzoylation and isolated in pure from by high-performance liquid chromatography. The desired acetates were obtained by Debenzoylation and acetylation of the pure isomers. Reported herein are the 1H NMR spectra of the benzoates and the electron-ionization mass spectra of the acetates and the tri-O-methyl derivative. Also reported for the acetates and the tri-O-methyl derivative are their linear temperature-programmed gas-liquid chromatography retention indices on three different capillary columns.
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Synthesis and characterization of authentic standards for the analysis of ribofuranose-containing carbohydrates by the reductive-cleavage method
Carbohydrate Research, 1995Co-Authors: Christine R. Rozanas, Nan Wang, Kathy Vidlock, Gary R. GrayAbstract:Abstract Described herein is the synthesis of all positional isomers of partially methylated and acetylated or benzoylated 1,4-anhydro- d -ribitol. The benzoates are generated simultaneously from 1,4-anhydro- d -ribitol by sequential partial methylation and benzoylation or sequential partial benzoylation and methylation. The individual isomers are obtained in pure form by high-performance liquid chromatography. Debenzoylation and acetylation provided the corresponding acetates. Reported herein are the 1 H NMR spectra of the benzoates and the electron-ionization mass spectra of the acetates and the tri- O -methyl derivative and also for the acetates and the tri- O -methyl derivative, their linear temperature programmed gas-liquid chromatography retention indices on three different capillary columns.
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Authentic standards for the reductive-cleavage method. The positional isomers of partially methylated and acetylated or benzoylated 1,5-anhydro-D-glucitol.
Carbohydrate research, 1995Co-Authors: Larry E. Elvebak, Gary R. GrayAbstract:Described is an efficient method for the synthesis of the sixteen positional isomers of methylated and acetylated or benzoylated 1,5-anhydro-D-glucitol. The compounds are generated simultaneously by partial methylation of 1,5-anhydro-D-glucitol and subsequent benzoylation, and the individual isomers are obtained in pure form by high-performance liquid chromatography. Debenzoylation of the latter and acetylation yielded the desired acetates. Reported are the 1H NMR spectra of the benzoates and the electron-ionization mass spectra of the acetates and the tetra-O-methyl derivative. Also reported for the acetates and the tetra-O-methyl derivative are their linear temperature programmed gas-liquid chromatography retention indices on three different capillary columns.
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Authentic standards for the reductive-cleavage method. The positional isomers of partially methylated and acetylated or benzoylated 1,4-anhydro-d-xylitol
Carbohydrate Research, 1995Co-Authors: Nan Wang, Gary R. GrayAbstract:Abstract Described herein is a general method for the synthesis of all positional isomers of methylated and acetylated or benzoylated 1,4-anhydro- d -xylitol. The benzoates are generated simultaneously from 1,4-anhydro- d -xylitol by sequential partial methylation and benzoylation or sequential partial benzoylation and methylation. The individual isomers are obtained in pure form by high-performance liquid chromatography. Debenzoylation and acetylation provided the corresponding acetates. The 1 H NMR spectra of the benzoates and the electron ionization mass spectra of the acetates and the tri- O -methyl derivative are reported herein as are the linear temperature programmed gas-liquid chromatography retention indices of the acetates and the tri- O -methyl derivative on three different capillary columns.
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Synthesis and characterization of authentic standards for the reductive-cleavage method. The positional isomers of partially methylated and acetylated or benzoylated 1,4-anhydro-L-fucitol.
Carbohydrate Research, 1995Co-Authors: Nan Wang, Larry E. Elvebak, Gary R. GrayAbstract:Abstract Described herein is the synthesis of all positional isomers of methylated and acetylated or benzoylated 1,4-anhydro- l -fucitol. The benzoates are generated simultaneously from 1,4-anhydro- l -fucitol by sequential partial methylation and benzoylation or sequential partial benzoylation and methylation. The individual isomers are obtained in pure form by high-performance liquid chromatography. Debenzoylation and acetylation provided the corresponding acetates. The 1 H NMR spectra of the benzoates and the electron-ionization mass spectra of the acetates and the tri- O -methyl derivative are reported herein as are the linear temperature programmed gas-liquid chromatography retention indices of the acetates and the tri- O -methyl derivative on three different capillary columns.
Miyeon Jang - One of the best experts on this subject based on the ideXlab platform.
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regioselective 2 o Debenzoylation of 2 3 di o benzoyl threose nucleosides
Tetrahedron Letters, 2013Co-Authors: Miyeon Jang, Matheus Froeyen, Piet HerdewijnAbstract:Abstract A simple and convenient procedure for the regioselective 2′-O-Debenzoylation of 2',3'-di-O-benzoyl threose nucleosides has been achieved successfully affording 3′-O-benzoyl threose nucleosides, which are useful starting material synthons for the synthesis of modified threose nucleosides for different purposes.
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Regioselective 2′-O-Debenzoylation of 2',3'-di-O-benzoyl threose nucleosides
Tetrahedron Letters, 2013Co-Authors: Miyeon Jang, Matheus Froeyen, Piet HerdewijnAbstract:Abstract A simple and convenient procedure for the regioselective 2′-O-Debenzoylation of 2',3'-di-O-benzoyl threose nucleosides has been achieved successfully affording 3′-O-benzoyl threose nucleosides, which are useful starting material synthons for the synthesis of modified threose nucleosides for different purposes.
