Table 2.
Photoglycosylation of Alcohols with Donors 6–9 and Catalytic 10
| |||||
|---|---|---|---|---|---|
|
| |||||
| entry | donor | acceptor (equiv) | photolysistime (h) | product | yield, %a α:β-ratiob |
| 1 |
 6α |
 11 (3) |
36 |
 14 |
80, 1.3:1 |
| 2 | 6α |
 12 (1.5) |
48 |
 15 |
62, 1.5:1 |
| 3 | 6α |
 13 (1.5) |
60 |
 16 |
64, 1:1 |
| 4 |
 7α |
11 (3) | 36 |
 17 |
96, 1:2.5 |
| 5 |
 7β |
11 (5) | 36 | 17 | 91, 1.2:1 |
| 6 | 7α | 12 (1.5) | 48 |
 18 |
88, 1:1 |
| 7 | 7β | 12 (1.5) | 48 | 18 | 79, 1.3:1 |
| 8 | 7α | 13 (1.5) | 48 |
 19 |
69, 1.3:1 |
| 9 | 7β | 13 (1.5) | 48 | 19 | 63, 1.6:1 |
| 10 |
 8α |
11 (3) | 36 |
 20 |
95, 1:1.6 |
| 11 |
 8β |
11 (3) | 36 | 20 | 87, 1.6:1 |
| 12 | 8α | 12 (1.5) | 48 |
 21 |
82, 1.2:1 |
| 13 | 8β | 12 (1.5) | 48 | 21 | 75, 1.4:1 |
| 14 | 8α | 13 (1.5) | 48 |
 22 |
77, 1.6:1 |
| 15 | 8β | 13 (1.5) | 48 | 22 | 59, 1.6:1 |
| 16 |
 9β |
11 (3) | 36 |
 23 |
86, 1.8:1 |
| 17 | 9β | 12 (1.5) | 72 |
 24 |
61, 1.4:1 |
| 18 | 9β | 13 (1.5) | 60 |
 25 |
57, 2:1 |
a
Combined yield of the isolated anomers.
b
Anomeric ratios were determined by integration of the 1H NMR spectra of the crude photolysates before purification