TY - JOUR
T1 - Glucosamine derived DISAL donors for stereoselective glycosylations under neutral conditions
AU - Grathe, S.
AU - Thygesen, M.B.
AU - Larsen, K.
AU - Petersen, L.
AU - Jensen, Knud Jørgen
PY - 2005
Y1 - 2005
N2 - DISAL (methyl 3,5-dinitrosa/icylate) D-glcosyl, D-galactosyl, D-mannosyl, and L-quinovosyl donors have previously provided the efficient glycosylation of a range of substrates under either strictly neutral, mildly basic, or very mildly Lewis acidic (LiClO4) conditions. Herein we report the synthesis of new glucosamine DISAL donors, carrying N-TCP, -Troc, or -TFAc protecting groups, and their use in beta-(1,2-trans) selective glycosylations, primarily in NMP in the absence of any added Lewis acids, or in CH3NO2 with LiClO4. Finally, precise microwave heating proved effective in promoting the difficult glycosylation of the 3-OH of a glucosamine derivative.
AB - DISAL (methyl 3,5-dinitrosa/icylate) D-glcosyl, D-galactosyl, D-mannosyl, and L-quinovosyl donors have previously provided the efficient glycosylation of a range of substrates under either strictly neutral, mildly basic, or very mildly Lewis acidic (LiClO4) conditions. Herein we report the synthesis of new glucosamine DISAL donors, carrying N-TCP, -Troc, or -TFAc protecting groups, and their use in beta-(1,2-trans) selective glycosylations, primarily in NMP in the absence of any added Lewis acids, or in CH3NO2 with LiClO4. Finally, precise microwave heating proved effective in promoting the difficult glycosylation of the 3-OH of a glucosamine derivative.
M3 - Journal article
SN - 0957-4166
VL - 16
SP - 1439
EP - 1448
JO - Tetrahedron-Asymmetry
JF - Tetrahedron-Asymmetry
IS - 8
ER -