反应详情

7.75 ml of oxalyl chloride (87 mmol) and 0.11 ml of N,N-dimethylformamide (1.4 mmol) were added to a solution of 19.02 g of (2S,4E)-6-(benzyloxy)-2-isopropylhex-4-enoic acid obtained in Example (1b) (72.5 mmol) in methylene chloride (180 ml) at room temperature. The mixture was stirred at the same temperature for one hour to prepare a solution of (2S,4E)-6-(benzyloxy)-2-isopropylhex-4-enoic acid chloride in methylene chloride. The solution of acid chloride in methylene chloride above was added to a solution of 76 ml of a 50% dimethylamine aqueous solution (725 mmol) in a mixed solvent of tetrahydrofuran (180 ml) and t-butanol under ice-cooling over one hour, and the mixture was stirred at the same temperature for 20 minutes. The reaction mixture was concentrated under reduced pressure to about ⅕ of the volume and diluted with 150 ml of water, followed by extraction with ethyl acetate. Then, the organic layer was washed with water, a saturated sodium bicarbonate aqueous solution and brine and dried over anhydrous magnesium sulfate. After filtration, the solvent was evaporated under reduced pressure to obtain 21.20 g of the crude title compound.

1. temperaturecooling over one hour
2. stirringthe mixture was stirred at the same temperature for 20 minutes
3. concentrationThe reaction mixture was concentrated under reduced pressure to about ⅕ of the volume
4. additiondiluted with 150 ml of water
5. extractionfollowed by extraction with ethyl acetate
6. washThen, the organic layer was washed with water
7. dry with materiala saturated sodium bicarbonate aqueous solution and brine and dried over anhydrous magnesium sulfate
8. filtrationAfter filtration
9. customthe solvent was evaporated under reduced pressure