Diethyl Carbonate → Ethyl 6-oxospiro[2.5]octane-5-carboxylate

To a stirred solution of spiro[2.5]octan-6-one (prepared according to the procedure reported in US2008176926) (0.900 g, 7.25 mmol) in dimethylformamide (10 ml) at 5° C. was added sodium hydride (0.580 g, 60%, 14.50 mmol) under a nitrogen atmosphere over a period of 10 min and the resulting mixture was stirred for an additional 20 min at the same temperature. To this reaction mixture, diethylcarbonate (1.72 g, 14.50 mmol) was added at 5° C. and stirred for 1 h and then allowed to stir at room temperature for 2 h. The progress of the reaction was monitored by TLC. The reaction mixture was cooled to 0° C. and quenched with saturated ammonium chloride (10 ml) and diluted with water (30 ml). The resulting mixture was extracted with diethyl ether (2×20 ml), and the combined organic layer was washed with water (2×20 ml), dried over anhydrous sodium sulphate, filtered, and the solvent was removed under reduced pressure to obtain a crude product which was purified by flash chromatography over silica gel (100-200 mesh) using 1% ethyl acetate in hexane as eluent to yield the title compound (0.510 g, 35.9%).

1. customat 5° C.
2. stirringstirred for 1 h
3. stirringto stir at room temperature for 2 h
4. customquenched with saturated ammonium chloride (10 ml)
5. additiondiluted with water (30 ml)
6. extractionThe resulting mixture was extracted with diethyl ether (2×20 ml)
7. washthe combined organic layer was washed with water (2×20 ml)
8. dry with materialdried over anhydrous sodium sulphate
9. filtrationfiltered
10. customthe solvent was removed under reduced pressure
11. customto obtain a crude product which
12. customwas purified by flash chromatography over silica gel (100-200 mesh)

ORD-Eintrag

ord-e53574cdf32e49b5b98813a82c4a1d80

Quelldatensatz

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09359367B2