反应详情

A mixture of iodide 43 (see Example 2C) (1.00 g, 2.49 mmol) and copper iodide (51 mg, 0.27 mmol) in DMF (10 mL) and Et3N (10 mL) was purged with N2. Ethynyltrimethylsilane (1.0 mL, 7.1 mmol) and PdCl2(PPh3)2 (93 mg, 0.13 mmol) were added and the mixture was stirred under N2 for 0.5 h. The resulting mixture was partitioned between EtOAc and water, the organic fraction was dried, and the solvent was removed. The residue was dissolved in THF (50 mL) and tetra-n-butylammonium fluoride (5 mL of a 1M solution in THF, 5 mmol) was added. The solution was stirred for 2 h and then concentrated. The residue was partitioned between EtOAc and water, and the organic fraction was dried and concentrated. Column chromatography of the residue on silca gel using gradient elution (1:1 hexanes EtOAc to EtOAc) gave (6S)-6-[(4-ethynylbenzyl)oxy]-2-nitro-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine (129) (0.530 g, 71%) as a white solid: mp 162-164° C.; 1H NMR [(CD3)2SO] δ 8.01 (s, 1H), 7.45 (d, J=8.3 Hz, 2H), 7.32 (d, J=8.3 Hz, 2H), 4.62-4.71 (m, 3H), 4.47 (d, J=11.9 Hz, 1H), 4.20-4.30 (m, 3H), 4.14 (s, 1H). Anal. (C15H13N3O4) C, H, N.

1. customwas purged with N2
2. customThe resulting mixture was partitioned between EtOAc and water
3. customthe organic fraction was dried
4. customthe solvent was removed
5. dissolutionThe residue was dissolved in THF (50 mL)
6. additiontetra-n-butylammonium fluoride (5 mL of a 1M solution in THF, 5 mmol) was added
7. stirringThe solution was stirred for 2 h
8. concentrationconcentrated
9. customThe residue was partitioned between EtOAc and water
10. customthe organic fraction was dried
11. concentrationconcentrated
12. washelution (1:1 hexanes EtOAc to EtOAc)