[CH3:1][C@H:2]([CH2:7][CH2:8][CH2:9][CH3:10])[CH2:3][C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.[CH3:16]O>>[CH3:1][C@H:2]([CH2:7][CH2:8][CH2:9][CH3:10])[CH2:3][C:4]([O:6][CH3:16])=[O:5]In a 500 ml flask were charged 300 ml of methanol, 35.5 g of (R)-3-methylheptanoic acid obtained in Step 3, and 0.5 g of concentrated sulfuric acid, and the mixture was heated at a methanol refluxing temperature for 18 hours. Methanol was distilled off under reduced pressure, and the residue was extracted with diethyl ether. The extract was washed with water, neutralized with a sodium carbonate aqueous solution, and then washed with a sodium chloride aqueous solution. Diethyl ether was removed by distillation, and the residue was distilled under reduced pressure to obtain 29 g (76.8%) of the titled compound (b.p.: 80° C./20 mmHg).
読み込み中…