Table 2.
Coupling of P4 position and deprotection of t-butyl group
| Entry | Subst | Conditionsa | Product | Entry | Subst | Conditionsa | Product |
|---|---|---|---|---|---|---|---|
| 1 | 4a | ![]() |
5a (38%) | 9 | 4a | ![]() |
5i (69%) |
| 2 | 4a | ![]() |
5b (79%) | 10 | 4a | ![]() |
5j (55%) |
| 3 | 4a | ![]() |
5c (37%) | 11 | 4a | ![]() |
5k (29%) |
| 4 | 4a | ![]() |
5d (43%) | 12 | 4b | ![]() |
5l (26%) |
| 5 | 4a | ![]() |
5e (80%) | 13 | 4c | ![]() |
5m(91%) |
| 6 | 4a | ![]() |
5f (7%) | 14 | 4d | ![]() |
5n (19%) |
| 7 | 4a | ![]() |
5g (23%) | 15 | 4e | ![]() |
5o (48%) |
| 8 | 4a | ![]() |
5h (29%) |
Reagents and conditions: (1) conditions A, B or C, DIPEA, CH2Cl2, rt, (2) 50% TFA/CH2Cl2, rt. (A) HATU, HOAt, (B) DMT-MM, (C) Et3N, DMAP.














