612844-16-3Relevant academic research and scientific papers
Extended applications of di-tert-butylsilylene-directed α-predominant galactosylation compatible with C2-participating groups toward the assembly of various glycosides
Imamura, Akihiro,Kimura, Akiyoshi,Ando, Hiromune,Ishida, Hideharu,Kiso, Makoto
, p. 8862 - 8870 (2007/10/03)
The high versatility of di-tert-butylsilylene(DTBS)-directed α-predominant galactosylation have been extended to the construction of difficult glycan sequences. First, to investigate the compatibility of the α-predominant reaction with various glycosylation systems a variety of 4,6-O-DTBS-tethered galactosaminyl or galactosyl donors were synthesized efficiently, which have C2-participating groups with a wide variety of leaving groups such as alkylsulfenyl, halide, trichloroacetimidate groups. The results of the detailed examination of the glycosylation reaction using the glycosyl donors showed the wide scope of the 4,6-DTBS-directed α-galactosylation. In the next step, the stereoselective construction of α GalN-Ser/Thr sequences was examined by employing the DTBS-directed glycosylation. As a result, various types of serine and threonine derivatives were glycosylated α-selectively, producing α-GalN-Ser/Thr sequences in high yields. Moreover, the DTBS-directed galactosylation was successfully applied for the synthesis of α-tetrasaccharyl-Ser segment of glycophorin A.
