反应详情

温度

70 °C

Glacial HOAc (120 mL) was added to a suspension of the product of Step 4 (32.4 g, approx. 103 mmol) in 210 mL of 30-32% anhydrous HBr in glacial HOAc (approx. 1.03 mol) to complete the dissolution. The resulting solution was stirred at 70° C. for 6 hours and at 50° overnight. The reaction mixture was then cooled to room temperature, diluted with H2O (750 mL) and extracted with CH2Cl2 (7×). The combined organic extracts were concentrated in vacuo. The residue was diluted with toluene (500 mL) and concentrated in vacuo 5 times to remove HOAc. The residue was dissolved in 1M aqueous KOH (750 mL), washed with CH2Cl2 (4×), acidified to pH 1 with concentrated HCl and extracted with CH2Cl2 (6×). The combined organic extracts were dried over Na2SO4 and concentrated in vacuo to afford a pale yellow liquid which was used as such for the next step. 1H NMR (CDCl3): δ0.91 (3H, t), 1.66 (2H, m), 2.44-2.56 (2H, m), 2.65-2.75 (1H, m), 3.73 (2H, s), 7.31 (5H, br s).

1. dissolutionthe dissolution
2. temperatureThe reaction mixture was then cooled to room temperature
3. extractionextracted with CH2Cl2 (7×)
4. concentrationThe combined organic extracts were concentrated in vacuo
5. additionThe residue was diluted with toluene (500 mL)
6. concentrationconcentrated in vacuo 5 times
7. customto remove HOAc
8. dissolutionThe residue was dissolved in 1M aqueous KOH (750 mL)
9. washwashed with CH2Cl2 (4×)
10. extractionextracted with CH2Cl2 (6×)
11. dry with materialThe combined organic extracts were dried over Na2SO4
12. concentrationconcentrated in vacuo
13. customto afford a pale yellow liquid which