Agents
used
for
the
Protection
and
Deprotection
of
Different
Reactive
Groups
of
nucleotides
used
in
Chemical
Synthesis
of
DNA -
| Protected group |
Protected by |
Protecting group removed by |
| Both phosphotriester and phosphite triester approaches |
| The free -NH2 group of |
| deoxyadenosine |
Benzoate |
Mild alkaline hydrolysis |
| deoxycytidine |
Benzoate |
Mild alkaline hydrolysis |
| deoxyguanosine |
Isobutyrate |
Mild alkaline hydrolysis |
| thymidine |
Not required |
Not required |
| Hydroxyl groups of |
| deoxyribose: 5'-OH |
Dimethoxytrityl [(MeO) 2Tr] or DMTr |
Gentle acid hydrolysis by benzene sulfonic acid or ZnBr2 |
| Phosphotriester approach only |
| Phosphorylation by |
P-Chlorophenyl-phosphorodichloridate |
Not Done |
| OH group of phosphate |
β-Cyanoethanol |
Triethyl amine |
|
