反应详情

A solution of 76 mg of ester 11 (0.17 mmol) in 1 mL of THF was hydrolyzed with 360 uL of aqueous lithium hydroxide (0.5M, 0.18 mmol)) and 0.2 mL of methanol at 24° C. for 6 h. The mixture was acidified by addition of solid sodium hydrogen sulfate (25 mg, 0.18 mmol) and the residual water was removed in vacuo. The residual solid was extracted with ethyl acetate and the product acid was purified by PLC on a 0.5 mm thick preparative silica gel plate eluted in 10% methanol:90% ethyl acetate. Extraction of the UV-active band yielded 43 mg of free acid 12 as an oil (54% yield); 1H NMR (CD3OD): 1.13 (d, J=6.3 Hz, 3H), 1.28-1.63 (m, 8H), 1.75-2.21 (m, 6H), 2.86 (t, J=7 Hz, 2H), 3.70 (m, 1H), 4.04 (m, 3H), 5.52 (m, 2H), 6.86 (br s, 1H), 7.58 (br s, 1H). HPLC purity was 100A %. LCMS (ESI: M+-H20): 413.2.

1. customat 24° C.
2. customfor 6 h
3. customthe residual water was removed in vacuo
4. extractionThe residual solid was extracted with ethyl acetate
5. customthe product acid was purified by PLC on a 0.5 mm thick preparative silica gel plate
6. washeluted in 10% methanol
7. extractionExtraction of the UV-active band