Acetic Anhydride → 3,5-Dioxohexanoic acid

To a solution of 1.28 g of 1-(2,4-dihydroxy-2,6,6-trimethylcyclohexyl)hex-1-en-3-ol in 50 ml of triethylamine was slowly added 1.2 ml of acetic anhydride under ice-cooling. To the mixture was further added 120 mg of p-dimethylaminopyridine. The mixture was allowed to stand at room temperature overnight. The reaction mixture was poured onto ice and extracted with diethyl ether. The extract was washed successively with a 0.5N hydrochloric acid aqueous solution and a saturated sodium chloride aqueous solution and dried over anhydrous magnesium sulfate, followed by filtration. The filtrate was concentrated under reduced pressure to obtain 1.25 g of a triacetate compound as an oily product. The resulting triacetate compound (1.21 g) was dissolved in 130 ml of carbon tetrachloride, followd by cooling to -5° C. to 0° C. with ice-cold sodium chloride. To the solution was slowly added dropwise 8.3 ml of bromine. After completion of the addition, the mixture was allowed to stand at 0° C. for 1 hour, washed successively with a 10% aqueous solution of sodium hydrogen carbonate and a saturated sodium chloride aqueous solution, and dried over ahhydrous magnesium sulfate. After filtration, the filtrate was concetrated under reduced pressure to obtain 1.95 g of an oily product.

1. temperaturecooling
2. additionThe reaction mixture was poured onto ice
3. extractionextracted with diethyl ether
4. washThe extract was washed successively with a 0.5N hydrochloric acid aqueous solution
5. dry with materiala saturated sodium chloride aqueous solution and dried over anhydrous magnesium sulfate
6. filtrationfollowed by filtration
7. concentrationThe filtrate was concentrated under reduced pressure

ORD record

ord-c2602214cf0e4b448fd94b53b24797e4

Source dataset

uspto-grants-1991_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04983723