反应详情

To a solution of 10.0 g (64.1 mmol) of (S)-(-)-citronellol 29 (Aldrich, 98% e.e.) in 150 ml of dry DMF is added 84.4 g (224 mmol) of pyridinium dichromate (PDC), and the mixture is stirred overnight. The reaction mixture is poured into 1.5 l of water, and extracted with toluene twice. The extract is washed with water, and then extracted with 1N aqueous solution of sodium hydroxide to separate the carboxylic acid. The aqueous layer is acidified with 5N hydrochloric acid to pH 2, and extracted with ethyl acetate again. The ethyl acetate extract is washed with water, a saturated aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate, and evaporated under reduced pressure. To a solution of residue in 100 ml of ether is added an ethereal solution of diazomethane at 0° C. until the yellow color persists. The reaction mixture is distilled under reduced pressure to give 7.53 g of the desired methyl ester 30 as an oil in 63.9% yield.

1. extractionextracted with toluene twice
2. washThe extract is washed with water
3. extractionextracted with 1N aqueous solution of sodium hydroxide
4. customto separate the carboxylic acid
5. extractionextracted with ethyl acetate again
6. extractionThe ethyl acetate extract
7. washis washed with water
8. dry with materiala saturated aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate
9. customevaporated under reduced pressure
10. additionTo a solution of residue in 100 ml of ether is added an ethereal solution of diazomethane at 0° C. until the yellow color persists
11. distillationThe reaction mixture is distilled under reduced pressure