R2
R1
R2
R1
1a
OH
5a
OH
1b
5b
1c
5c
2a
OH
6a
OH
2b
6b
2c
6c
3a
OH
7a
OH
3b
7b
3c
7c
3d
NH2
8a
OH
4a
OH
8b
4b
8c
NH2
4c
|
| R2 | R1 |
| R2 | R1 |
| 1a |
| OH | 5a |
| OH |
| 1b |
|
| 5b |
|
|
| 1c |
|
| 5c |
|
|
| 2a |
| OH | 6a |
| OH |
| 2b |
|
| 6b |
|
|
| 2c |
|
| 6c |
|
|
| 3a |
| OH | 7a |
| OH |
| 3b |
|
| 7b |
|
|
| 3c |
|
| 7c |
|
|
| 3d |
| NH2 | 8a |
| OH |
| 4a |
| OH | 8b |
|
|
| 4b |
|
| 8c |
| NH2 |
| 4c |
|
|
| ||