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Glycosyl Phosphites as Glycosyl Donors – A Comparative Study
Author(s) -
Müller Thomas,
Hummel Gerd,
Schmidt Richard R.
Publication year - 1994
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199419940403
Subject(s) - chemistry , glycosyl , disaccharide , yield (engineering) , acceptor , trisaccharide , glycosyl donor , fucose , glycosylation , lactose , catalysis , derivative (finance) , lewis acids and bases , organic chemistry , medicinal chemistry , galactose , stereochemistry , biochemistry , materials science , physics , economics , financial economics , metallurgy , condensed matter physics
Tri‐ O ‐benzyl‐ L ‐fucose ( 3 ) was transformed into the bis(trichloroethyl) phosphite derivative 4 which was allowed to react with 3‐ O ‐unprotected azidoglucose 7 as fucosyl acceptor in the presence of TMSOTf as catalyst to furnish disaccharide building block 1 , useful in Lewis antigen X (Le X ) synthesis, in 75% yield. Similarly, 2,3,4,6‐tetra‐ O ‐acetyl‐ D ‐galactose ( 8 ) was transformed into the bis(trichloroethyl) phosphite derivative 9 which afforded by treatment with acceptor 7 disaccharide 10 in 64% yield. The reaction of the derived acceptor 11 with donor 4 furnished trisaccharide building block 12 , useful in Lewis antigen A (Le a ) synthesis, in 88% yield. Transformation into the less reactive donor 14 and reaction with lactose acceptor 15 gave pentasaccharide 2 only in modest yield, thus exhibiting the scope and limitations of phosphite leaving groups in glycosylation reactions.