632
3
Chemical Glycosylation Reactions
⊡ Scheme 64
2 -Carboxybenzyl (CB) glycosides
⊡ Table 12
β-Mannopyranosylation with 2 -carboxybenzyl glycosides
Entry
Glycosyl acceptor (ROH)
Solvent
β/α ratio
Yield (%)
i
CH 2 Cl 2
β only
91
ii
389
toluene
20:1
95
iii
CH 2 Cl 2
β only
91
iv
CH 2 Cl 2
> 20:1
91
v
CH 2 Cl 2
17:1
96
vi
CH 2 Cl 2
> 20:1
90
5 2 -Carboxybenzyl (CB) Glycosides
Kim and co-workers introduced a novel type of O-glycosyl donor, the 2 -carboxybenzyl (CB)
glycoside 391b, readily available by selective hydrogenolysis of the benzyl ester functionality
3
Chemical Glycosylation Reactions
⊡ Scheme 64
2 -Carboxybenzyl (CB) glycosides
⊡ Table 12
β-Mannopyranosylation with 2 -carboxybenzyl glycosides
Entry
Glycosyl acceptor (ROH)
Solvent
β/α ratio
Yield (%)
i
CH 2 Cl 2
β only
91
ii
389
toluene
20:1
95
iii
CH 2 Cl 2
β only
91
iv
CH 2 Cl 2
> 20:1
91
v
CH 2 Cl 2
17:1
96
vi
CH 2 Cl 2
> 20:1
90
5 2 -Carboxybenzyl (CB) Glycosides
Kim and co-workers introduced a novel type of O-glycosyl donor, the 2 -carboxybenzyl (CB)
glycoside 391b, readily available by selective hydrogenolysis of the benzyl ester functionality