Chloroselenobenzene → Racemic ethyl 2,4-dimethyl-6-oxocyclohex-1-enecarboxylate

Temperatur

0 °C

Ethyl 2,4-dimethyl-6-oxocyclohexanecarboxylate (from Step 2, 0.5 g) was added dropwise to a stirred suspension of sodium hydride (60% in mineral oil, 0.15 g, washed with hexane) in THF at 0° C. After addition was complete, the mixture was stirred at 0° C. for 10 min and then a solution of phenylselenium chloride (0.58 g) in THF was added dropwise. The resulting mixture was slowly warmed to rt where it stirred overnight. After this time, the mixture was treated with saturated aqueous sodium bicarbonate and extracted three times with ethyl acetate. The combined organic layers were concentrated under vacuum and the resulting residue was dissolved in dichloromethane. This solution was treated with 30% aqueous hydrogen peroxide (3×0.3 mL, added at 10 min intervals) and the mixture was stirred for an additional 30 min. At the conclusion of this period, the mixture was washed with water and concentrated under vacuum to yield a residue. This residue was purified by column chromatography on silica gel, eluting with 10% ethyl acetate/hexanes, to provide racemic ethyl 2,4-dimethyl-6-oxocyclohex-1-enecarboxylate as an oil (200 mg).

1. additionAfter addition
2. temperatureThe resulting mixture was slowly warmed to rt where it
3. stirringstirred overnight
4. extractionextracted three times with ethyl acetate
5. concentrationThe combined organic layers were concentrated under vacuum
6. dissolutionthe resulting residue was dissolved in dichloromethane
7. additionThis solution was treated with 30% aqueous hydrogen peroxide (3×0.3 mL, added at 10 min intervals)
8. stirringthe mixture was stirred for an additional 30 min
9. washAt the conclusion of this period, the mixture was washed with water
10. concentrationconcentrated under vacuum
11. customto yield a residue
12. customThis residue was purified by column chromatography on silica gel
13. washeluting with 10% ethyl acetate/hexanes

ORD-Eintrag

ord-f6613d69ca2341639a761b055e9ce071

Quelldatensatz

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08507559B2