反应详情

温度

0 °C

The resultant acid from Example 23 (500 mg, 1.68 mmol) in CH2Cl2 (8 ml) at 0° C. was treated with oxalyl chloride (0.160 ml, 1.83 mmol) and dimethylformamide (0.0065 ml). After 2 h at 0° C., the solvent was evaporated and the residue was dissolved in ether (6 ml), cooled to 0° C. and treated with an ether solution of CH2N2. After 2 h at 0° C. the solvent was evaporated and the residue was dissolved in ether (6 ml), cooled to -10° C., and treated with 4.0M HCl/ dioxane (0.6 ml, 2.4 mmol). After 1 h the solvent was evaporated and the residue was chromatographed on silica gel with 10% ethyl acetate in hexane to afford 476.8 mg (83%) of a colorless oil. 1H NMR (CDCl3) δ7.08-7.40 (m,10H), 5.12 (d,1H), 5.08 (d,1H), 4.02 (s,2H), 3.30 (m,1H), 3.10 (dd,1H), 2.97 (dd,1H), 2.78 (dd,1H), 2.55 (dd,1H).

1. customthe solvent was evaporated
2. dissolutionthe residue was dissolved in ether (6 ml)
3. additiontreated with an ether solution of CH2N2
4. customAfter 2 h at 0° C. the solvent was evaporated
5. dissolutionthe residue was dissolved in ether (6 ml)
6. temperaturecooled to -10° C.
7. customAfter 1 h the solvent was evaporated
8. customthe residue was chromatographed on silica gel with 10% ethyl acetate in hexane