Table 1.
Acid lability studies of Fmoc‐Trp(Boc)‐OH and Fmoc‐Trp(Thp)‐OH.[a]
| Entry | Compound | Cocktail | Reaction time [min] | Deprotected amino acid [%] |
|---|---|---|---|---|
| 1 | Fmoc‐Trp(Boc)‐OH | TFA/CH2Cl2 (10:90) | 10 | 28 |
| 2 | 30 | 59 | ||
| 3 | 60 | 82 | ||
| 4 | TFA/H2O/CH2Cl2 (10:2:88) | 10 | 0 | |
| 5 | 30 | 42 | ||
| 6 | 60 | 69 | ||
| 7 | TFA/CH2Cl2 (60:40) | 10 | >99 | |
| 8 | Fmoc‐Trp(Thp)‐OH | TFA/CH2Cl2 (10:90) | 10 | 63 |
| 9 | 30 | 68 | ||
| 10 | 60 | 77 | ||
| 11 | TFA/H2O/CH2Cl2 (10:2:88) | 10 | 72 | |
| 12 | 30 | 79 | ||
| 13 | 60 | 90 | ||
| 14 | TFA/CH2Cl2 (60:40) | 10 | 59 | |
| 15 | 30 | 73 | ||
| 16 | 60 | 90 | ||
| 17 | TFA/H2O/CH2Cl2 (60:10:30) | 10 | 92 | |
| 18 | 30 | 94 | ||
| 19 | 60 | 96 |
[a] Unpublished data from our group.