- An effective and convenient synthesis of cordycepin from adenosine
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Cordycepin is a purine nucleoside analog with potent and diverse biological activities. Herein, we designed two methods to synthesize cordycepin. One method mainly converted the 3′-OH group into an iodide group and further dehalogenation to yield the final product. Although this method presented a short synthetic procedure, the synthesis had a low overall yield, resulting in only 13.5% overall yield. To improve the overall yield of cordycepin, another synthetic route was studied, which consisted of four individual steps: (1) 5′-OH protection (2) esterification (3) -O-tosyl (-OTs) group removal (4) deprotection. The key step in the synthetic method involved the conversion of 5′-O-triphenylmethyladenosine to 3′-O-tosyl-5′-O-triphenylmethyladenosine, using LiAlH4 as reducing agent. The main advantages of this route were an acceptable total product yield and the commercial availability of all starting materials. The optimal reaction conditions for each step of the route were identified. The overall yield of cordycepin obtained from adenosine as the starting material was 36%.
- Huang, Shen,Liu, Hui,Sun, Yanhua,Chen, Jian,Li, Xiufang,Xu, Jiangfeng,Hu, Yuwei,Li, Yuqing,Deng, Zhiwei,Zhong, Shian
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p. 149 - 160
(2018/01/17)
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- REACTION OF ADENINE NUCLEOSIDES, TOSYLATED IN THE CARBOHYDRATE MOIETY, WITH LITHIUM TRIETHYLBOROHYDRIDE
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The reaction of lithium triethylborohydride with the 2',3'-di-O-p-tolylsulphonyl derivatives of 9-β-D-ribofuranosyladenine, 9-β-D-arabinofuranosyladenine, 9-β-D-xylofuranosyladenine and 9-β-D-lyxofuranosyladenine was studied.The reaction of 2',3'-di-O-p-tolylsulphonyladenosine with LiEt3BH gave 9-(3-deoxy-β-D-threo-pentofuranosyl)adenine.This rearrangement reaction was used for the synthesis of 9-(3,5-dideoxy-β-D-threo-pentofuranosyl)adenine in one step from 2',3',5'-tri-O-p-tolylsulphonyladenosine in 58percent yield.The p-tolylsulphonyl group in the 2'-"up" configuration of unprotected adenine nucleosides was preferentially attacked by LiEt3BH giving S-O-bond scission.This was shown by the formation of 9-(3-deoxy-β-D-threo-pentofuranosyl)adenine from 2',3'-di-O-p-tolylsulphonyl-9-β-D-arabinofuranosyladenine and by the formation of 9-β-D-lyxofuranosyladenine from 2'-O-p-tolylsulphonyl-9-β-D-lyxofuranosyladenine with LiEt3BH. 9-β-D-Lyxofuranosyladenine was synthesized from 3',5'-di-O-benzoyl-9-β-D-xylofuranosyladenosine in 88percent yield using a triflate displacement reaction.
- Herdewijn, Piet
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p. 6563 - 6580
(2007/10/02)
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- Synthesis and anti-HIV activity of various 2'- and 3'-substituted 2',3'-dideoxyadenosines: A structure-activity analysis
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A systematic synthesis was undertaken of 2',3'-dideoxyadenosine analogues with either an azido, fluorine, or hydroxyl group substituted in the 'up' or 'down' position of C-2 or C-3 of the sugar moiety. The compounds were evaluated against the cytopathogen
- Herdewijn,Pauwels,Baba,Balzarini,De Clercq
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p. 2131 - 2137
(2007/10/02)
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- 2' AND 3'-KETONUCLEOSIDES AND THEIR ARABINO AND XYLO REDUCTION PRODUCTS CONVENIENT ACCESS VIA SELECTIVE PROTECTION AND OXIDATION OF RIBONUCLEOSIDES
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A number of 2',5'- or 3',5'-diprotected ribonucleosides and 5'-protected 2'- or 3'-deoxy-β-D-erythro-pentofuranosyl nucleosides have been oxidized to the corresponding 3' or 2'-ketonucleoside derivatives using chromium trioxide/pyridine/acetic anhydride or dimethyl sulfoxide/acetic anhydride.Reduction of the carbonyl functions with sodium borohydride gave the inverted arabino, xylo, or deoxy-threo isomers as predominant products by attack at the less hindered α-face of the sugar ring.Parallel reductions using sodium borodeuteride corroborated the epimeric ratios by demonstrating that complete oxidation of the original hydroxyl groups had occured.The deuterium labeling also aided in making NMR spectral assignments.
- Hansske, Fritz,Madej, Danuta,Robins, Morris J.
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p. 125 - 135
(2007/10/02)
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