Butyl oxoacetate → HCID 19922580, compound

Temperature

0 °C

0.5 ml (0.1 mmol) of (R)-1 solution prepared in the same manner as in Example 1 were cooled to 0° C., and 190 mg (1 mmol) of (E)-1-ethylthio-1-trimethylsilyloxy-1-propene (77% E) and subsequently 130 mg (1 mmol) of freshly distilled butyl glyoxylate and 0.5 ml of toluene were added thereto, followed by allowing the mixture to react at 0° C. for 0.5 hour. The resulting mixture was poured into 10% hydrochloric acid-methanol cooled at 0° C. The solution was filtered through a pad of Celite, and the filtrate was extracted three times with a 5 ml portion of diethyl ether. The combined organic layer was washed with a saturated sodium chloride aqueous solution, dried over magnesium sulfate and evaporated under reduced pressure to remove the solvent. The residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=15/1 by volume) to obtain 158 mg (yield 64%) of n-butyl 4-ethylthio-2-hydroxy-3-methyl-4-oxobutyrate.

1. customto react at 0° C. for 0.5 hour
2. temperaturecooled at 0° C
3. filtrationThe solution was filtered through a pad of Celite
4. extractionthe filtrate was extracted three times with a 5 ml portion of diethyl ether
5. washThe combined organic layer was washed with a saturated sodium chloride aqueous solution
6. dry with materialdried over magnesium sulfate
7. customevaporated under reduced pressure
8. customto remove the solvent
9. customThe residue was purified by silica gel column chromatography (eluent: hexane/ethyl acetate=15/1 by volume)

ORD record

ord-7d08826655fe4c6daa45d67a3037c698

Source dataset

uspto-grants-1995_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05434289