3-Methylidenebicyclo[2.2.1]heptan-2-one → Spiro[bicyclo[2.2.1]heptane-2,1'-cyclopropan]-3-one

Zinc powder (15.10 g) was suspended in diethyl ether (70 mL) and to which cuprous chloride (2.29 g) was added at room temperature, followed by 30 minutes' refluxing in nitrogen atmosphere. The suspension was cooled to 0° C. and to which 3-methylenebicyclo[2.2.1]heptan-2-one (7.0 mL) was added at 0° C. Into the reaction mixture, methane diiodide (7.0 mL) was slowly dropped at 0° C. and after the end of the dropping, the reaction mixture was refluxed for 30 hours in nitrogen atmosphere. Cooling the reaction mixture to room temperature, the insoluble matter was filtered off with Celite® and the filterate washed twice with 5% aqueous sodium thiosulfate solution. The organic layer was dried over anhydrous magnesium sulfate, the solvent was removed by distillation, and the resulting residue was purified on silica gel column chromatography (hexane/ethyl acetate=100/1−7/1) to provide 4.89 g of the title compound as a colorless oily substance.

1. additionwas added at room temperature
2. temperature' refluxing in nitrogen atmosphere
3. additionwas added at 0° C
4. temperatureafter the end of the dropping, the reaction mixture was refluxed for 30 hours in nitrogen atmosphere
5. filtrationthe insoluble matter was filtered off with Celite®
6. washthe filterate washed twice with 5% aqueous sodium thiosulfate solution
7. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
8. customthe solvent was removed by distillation
9. customthe resulting residue was purified on silica gel column chromatography (hexane/ethyl acetate=100/1−7/1)

ORD record

ord-58ebe4b9beb848189e4c588bb5ea758e

Source dataset

uspto-grants-2007_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07300947B2