反应详情

A solution of 6-[2-(5-ethoxycarbonyl-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid ethyl ester (870 mg, 1.89 mmol) and potassium hydroxide (85%, 750 mg, 11.33 mmol) in ethanol (16 mL) and water (4 mL) was heated under reflux for 3 h. The reaction mixture was diluted with water (100 mL) and acidified to pH 4 with 1 N HCl (8 mL). The emulsion was extracted with dichloromethane (3 75 mL). The combined organic phases were washed with water (50 mL), dried over MgSO4, concentrated in vacuo, and dried in high vacuo to furnish 6-[2-(5-carboxy-5-methyl-hexyl)-[1,3]dithian-2-yl]-2,2-dimethyl-hexanoic acid (730 mg, 95%) as a viscous, yellowish oil. 1H NMR (300 MHz, CDCl3/TMS): (ppm): 2.80 (m, 4H), 1.94 (m, 2H), 1.85 (m, 4H), 1.56 (m, 4H), 1.41 (m, 4H), 1.30 (m, 4H), 1.19 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): (ppm): 185.08, 53.36, 42.28, 40.52, 38.27, 26.18, 25.69, 25.23, 25.11, 24.73. HRMS (LSIMS, nba): Calcd. for C20H37O4S2 (MH+): 405.2133. found: 405.2115.

1. temperatureunder reflux for 3 h
2. extractionThe emulsion was extracted with dichloromethane (3 75 mL)
3. washThe combined organic phases were washed with water (50 mL)
4. dry with materialdried over MgSO4
5. concentrationconcentrated in vacuo
6. customdried in high vacuo