反应详情

温度

110 °C

A solution of LiOH (27 mg, 1.1 mmol) in H2O (0.5 ml) was added to a stirred solution of the ester (Step 1, 100 mg, 0.22 mmol) in THF (1 ml) at room temperature. After 60 hours an extra portion of LiOH (30 mg) and dioxane (1 ml) were added. The mixture was heated at 110° C. for 16 hours. After cooling to room temperature the mixture was acidified with 5N HCl. The mixture was partitioned between EtOAc/H2O. The layers were separated and the aqueous layer was further extracted with EtOAc (×2). The combined extracts were washed with brine (×1), dried (Na2SO4), filtered and evaporated. The residue was purified by reverse phase HPLC to give the acid as a 3:2 mixture of diastereomers (90 mg, 94%) as colourless solid. 1H NMR (500 MHz, CDCl3) δ: 1.12-1.14 (6H, m), 1.21-1.26 (3H, m), 2.01-2.25 (3H, m), 2.26-2.40 (1H, m), 2.50-2.59 (2H, m), 2.78-2.83 (1H, m), 3.48-3.51 (1H, m), 3.91-3.95 (1H, m), 4.35-4.40 (1H, m), 7.12-7.14 (2H, m), 7.24-7.26 (2H, m), 7.42-7.53 (4H, m); M/Z (ES+) 420 (MH+).

1. temperatureAfter cooling to room temperature the mixture
2. customThe mixture was partitioned between EtOAc/H2O
3. customThe layers were separated
4. extractionthe aqueous layer was further extracted with EtOAc (×2)
5. washThe combined extracts were washed with brine (×1)
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. customevaporated
9. customThe residue was purified by reverse phase HPLC
10. customto give the acid
11. additionas a 3:2 mixture of diastereomers (90 mg, 94%) as colourless solid