402948-43-0Relevant academic research and scientific papers
One-pot synthesis of sialo-containing glycosyl amino acids by use of an N-trichloroethoxycarbonyl-β-thiophenyl sialoside
Tanaka, Hiroshi,Adachi, Masaatsu,Takahashi, Takashi
, p. 849 - 862 (2007/10/03)
We describe an efficient synthesis of 2,6- and 2,3-sialyl T antigens linked to serine in a one-pot glycosylation. We first investigated the glycosidation of thiosialosides by varying the N-protecting group. Modification of the C-5 amino group of β-thiosialosides into the N-9-fluorenylmethoxycarbonyl, N-2,2,2-trichloroethoxycarbonyl (N-Troc), and N-trichloroacetyl derivatives enhanced the reactivity of these compounds towards glycosidation. Addition of a minimum amount of 3 A molecular sieves was also effective in improving the yield of α-linked sialosides. Next, we conducted one-pot syntheses of the glycosyl amino acids by using the N-Troc sialyl donor. The N-Troc derivative can be converted into the N-acetyl derivative without racemization of the amino acids. Branched-type one-pot glycosylation, initiated by regioselective glycosylation of the 3,6-dihydroxy galactoside with the N-Troc-β-thiophenyl sialoside, provided the protected 2,6-sialyl T antigen in good yield. Linear-type one-pot glycosylation, initiated by chemoselective glycosylation of galactosyl fluoride with the N-Troc-β-thiophenyl sialoside, afforded the protected 2,3-sialyl T antigen in excellent yield. Both protected glycosyl amino acids were converted into the fully deprotected 2,6- and 2,3-sialyl T antigens linked to serine in good yields.
An effective sialylation method using N-Troc- and N-Fmoc-protected β-thiophenyl sialosides and application to the one-pot two-step synthesis of 2,6-sialyl-T antigen
Adachi, Masaatsu,Tanaka, Hiroshi,Takahashi, Takashi
, p. 609 - 614 (2007/10/03)
We describe an efficient sialylation method using β-thiosialosides with various N-protecting groups. Modification of the C-5 amino group of β-thiosialosides into N-Fmoc and N-Troc derivatives enhanced their reactivity in glycosidation. In addition, a minimum amount of MS-3 A? was effective to improve the yield of α-linked sialoside. Branched type one-pot glycosylation initiating glycosidation of the N-Troc-protected β-thiophenyl sialoside at a primary alcohol provided the protected 2,6-sialyl-T antigen in good yield, which was converted to the fully deprotected glycosyl amino acid.
Extending the possibility of an N-Troc-protected sialic acid donor toward variant sialo-glycoside synthesis
Ando, Hiromune,Koike, Yusuke,Ishida, Hideharu,Kiso, Makoto
, p. 6883 - 6886 (2007/10/03)
The potential of an N-Troc-protected sialic acid donor, equipped with phenylsulfenyl functionality as a leaving group, has been explored. As a result, the entitled donor was proven to be highly reactive and to have broad applicability toward the synthesis of variant sialo-glycans, which have N-glycolyl, de-N-acetyl, 1,5-lactam and 8-O-sulfo sialic acid analogs.
Synthesis of a sialic acid dimer derivative, 2′α-O-benzyl Neu5Ac-α-(2→5)Neu5Gc
Ren, Chien-Tai,Chen, Chien-Sheng,Wu, Shih-Hsiung
, p. 1376 - 1379 (2007/10/03)
The preparation of a disaccharide 2, Neu5Ac-α-(2→5)Neu5Gc having a α-benzyl protecting group at the reducing end, by the coupling of the easily accessible building units 4 and 5 is described. Subsequent deprotection of the coupling adduct led to the isolation of the target compound 2 in high yield.
