Mannose acceptors and the stereoselectivity of glycosylation reactions with donor A and donor B.
| Acceptor | Structure | Donor A | Donor B | ||||
|---|---|---|---|---|---|---|---|
| Product (yield%) | α : βb | β (%) | Product (yield%) | α : βb | β (%) | ||
| 19a |
|
19A (76) | 1 : 2 | 67 | 19B (72) | <1 : 20 | 100 |
| 20 |
|
20A (76) | 1.3 : 1 | 43 | 20B (92) | 1 : 8 | 89 |
| 21 |
|
21A (62) | 9 : 1 | 10 | 21B (93) | 1.5 : 1 | 40 |
| 22 |
|
22A (66) | >20 : 1 | 0 | 22B (98) | 10 : 1 | 9 |
| 23a |
|
23A (82) | 8 : 1 | 11 | 23B (70) | 1.1 : 1 | 48 |
| 24 |
|
24A (87) | >20 : 1 | 0 | 24B (87) | >20 : 1 | 0 |
| 25 |
|
25A (82) | 10 : 1 | 9 | 25B (93) | 1 : 1 | 50 |
| 26a |
|
26A (100) | >20 : 1 | 0 | 26B (100) | >20 : 1 | 0 |
| 27a |
|
27A (95) | >20 : 1 | 0 | 27B (65) | 7 : 1 | 13 |
| 28 |
|
28A (76) | >20 : 1 | 0 | 28B (51) | 7 : 1 | 13 |
| 29 |
|
29A (77) | >20 : 1 | 0 | 29B (51) | >20 : 1 | 0 |
a
Taken from ref. 11.
b
The anomeric ratio was determined using NMR of the product mixtures, isolated by size exclusion chromatography, see ESI for details.