反应详情

A solution of the product from EXAMPLE 5 (6, 250 mg, 0.4 mMol) in THF (36 mL) was treated with 1N HCl (0.4 mL) was kept at 45-47° C. in for 24 hours. The reaction mixture was cooled to room temperature. TLC (DCM-MeOH 95:5) shows no 4 (Rf=0.75) and one major product (Rf=0.45). The solution was concentrated on a rotary evaporator to remove THF. The resulting mixture was partitioned between EtOAc (100 mL) and saturated aqueous NaCl (50 mL). The organic layer was separated and allowed to stand for 15 minutes. The organic solution was decanted from some aqueous droplets. The last two steps (standing and decanting) were repeated. The resulting EtOAc solution was then evaporated at reduced pressure to give an orange gum. The gum was dissolved in DCM (20 mL) and evaporated at reduced pressure twice to give an orange foam which was further dried in vacuo for 4 hours. The foam was dissolved in 0.5 M LiOH (3.4 mL, 1.7 mMol). The resulting black solution was stirred at room temperature for 24 hours. The reaction mixture was then acidified by dropwise addition of concentrated HCl (0.25 mL, 3 mMol) to give red solution. The solution was partitioned between EtOAc (50 mL), water (5 mL) and saturated aqueous NaCl (5 mL). The organic layer was separated and allowed to stand for 15 minutes. The organic solution was decanted from some aqueous droplets. Evaporation of solvent at reduced pressure gave a red gum. The gum was triturated with DCM and the resulting slurry was evaporated at reduced pressure. The resulting solid was triturated with DCM-hexanes (1:1), the solvent was decanted from the red-brown solid, and the solid was dried in vacuo to afford 7 (94 mg 43%). MS (AP− taken from a MeOH solution) 577 (M+MeOH-1), 545 (M−1).

1. customwas kept at 45-47° C. in for 24 hours
2. concentrationThe solution was concentrated on a rotary evaporator
3. customto remove THF
4. customThe resulting mixture was partitioned between EtOAc (100 mL) and saturated aqueous NaCl (50 mL)
5. customThe organic layer was separated
6. customThe organic solution was decanted from some aqueous droplets
7. customThe last two steps (standing and decanting)
8. customThe resulting EtOAc solution was then evaporated at reduced pressure
9. customto give an orange gum
10. customevaporated at reduced pressure twice
11. customto give an orange foam which
12. customwas further dried in vacuo for 4 hours
13. customto give red solution
14. customThe solution was partitioned between EtOAc (50 mL), water (5 mL) and saturated aqueous NaCl (5 mL)
15. customThe organic layer was separated
16. waitto stand for 15 minutes
17. customThe organic solution was decanted from some aqueous droplets
18. customEvaporation of solvent at reduced pressure
19. customgave a red gum
20. customThe gum was triturated with DCM
21. customthe resulting slurry was evaporated at reduced pressure
22. customThe resulting solid was triturated with DCM-hexanes (1:1)
23. customthe solvent was decanted from the red-brown solid
24. customthe solid was dried in vacuo
25. customto afford 7 (94 mg 43%)