22224-38-0Relevant articles and documents
Synthesis of novel 6-substituted thymine ribonucleosides and their 3′-fluorinated analogues
Bozhok, Tatyana S.,Sivets, Grigorii G.,Baranovsky, Alexander V.,Kalinichenko, Elena N.
, p. 6518 - 6527 (2016/09/23)
Nine novel 6-fluorothymine nucleoside analogues of both N(1)-α/β and N(3)-β-ribo series were prepared by the Vorbrüggen method starting from persilylated 6-fluorothymine and 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose, 1-O-acetyl-2,5-di-O-benzoyl-3-deoxy-3-fluoro-α,β-D-ribofuranose or 1,2,3,5-tetra-O-benzoyl-β-D-ribofuranose and its α-anomer. Protected N(3)-β-D-ribofuranosides were prepared as sole products in high yields at room temperature. A mixture of benzoylated N(1)-β- and α-anomeric ribonucleosides was obtained at lower temperatures. Yields of β-anomers and stereoselectivities (β:α=2.2/4.5:1) of the condensation reactions depended on reaction conditions and the structure of the glycosylating agent. Debenzoylation of 6-fluorothymine N(1)- or N(3)-β-D-ribofuranosides and their 3′-fluorodeoxy analogues by LiOH monohydrate in MeCN/H2O resulted in the corresponding fluorinated nucleosides in good yields, whereas the deprotection of N(1)-α-ribofuranosides under the same conditions unexpectedly yielded 6,2′-O-α-D-anhydronucleosides. 6-Substituted (OMe, NH2) thymine β-ribonucleosides were prepared by the treatment of protected N(1)-β-D-ribosides with nucleophilic agents.
Synthesis of Glycosyl Trifluoroacetates and Their Reactions with Carboxylic Acids
Kobayashi, Miyuki,Shimadate, Toshisada
, p. 4069 - 4074 (2007/10/02)
2,3,4,6-Tetra-O-acetyl-1-O-trifluoroacetyl-α-D-glucopyranose was prepared in high yield by treating 1,2,3,4,6-penta-O-acetyl-α- or -β-D-glucopyranose with a mixture of trifluoroacetic acid and its anhydride in the presence of trifluoromethanesulfonic acid or antimony (V) fluoridegraphite catalyst.The reaction of the trifluoroacetate with some carboxylic acids afforded the corresponding 1-O-acyl-2,3,4,6-tetra-O-acetyl-α-D-glucopyranoses.By a similar procedure, anomeric 1-O-trifluoroacetyl-2,3,5-tri-O-benzoyl- and -2,3,5-tri-O-acetyl-D-ribofuranose were obtained from 1-O-acetyl-2,3,5-tri-O-benzoyl- and 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose respectively, and these trifluoroacetates were allowed to react with some carboxylic acids to yield the corresponding 1-O-acyl-β-D-ribofuranose benzoates and acetates.These products were also prepared by direct fusion of 1-O-acetyl-β-D-ribofuranose benzoate and acetate with carboxylic acids.Keywords-glycosyl trifluoroacetate; glycosyl carboxylate; fusion reaction; tetra-O-acetyl-α-D-glucopyranosyl trifluoroacetate; tri-O-benzoyl-α,β-D-ribofuranosyl trifluoroacetate; tri-O-acetyl-α,β-D-ribofuranosyl trifluoroacetate
