Methanol → Tert-Butyl 1-(2-oxoethyl)cyclopropanecarboxylate

Temperature

-72 °C

6.9 g (36.34 mmol, 1 equiv., 96% a % by GC) 1-allyl-cyclopropanecarboxylic acid tert-butyl ester were dissolved in 40 ml dichloromethane and 40 ml methanol. The solution was cooled to −72° C. and the ozone was bubbled through the reaction mixture until a blue color was obtained. Then nitrogen was bubbled to remove excess ozone until a colorless solution was obtained. 10 ml (3.68 equiv.) dimethyl sulfide and 14 ml (2.76 equiv.) triethylamine were added. The reaction mixture was warmed to room temperature and stirred overnight at that temperature (peroxide test negative, pH 7-8). The yellowish reaction mixture was added to 100 ml sat aq. ammonium chloride solution (exothermic) and extracted 3 times with 70 ml dichloromethane. The organic phases were combined, dried over sodium sulfate, filtered and concentrated under reduced pressure to provide the crude aldehyde, which was purified by filtration over SiO2 (dichloromethane; TLC: ethyl acetate/heptane 1:2) to provide 3.90 g (96% GC, 56% yield) of the title compound as an oil.

1. customthe ozone was bubbled through the reaction mixture until a blue color
2. customwas obtained
3. customThen nitrogen was bubbled
4. customto remove excess ozone until a colorless solution
5. customwas obtained
6. temperatureThe reaction mixture was warmed to room temperature
7. customThe yellowish reaction mixture
8. additionwas added to 100 ml
9. extractionextracted 3 times with 70 ml dichloromethane
10. dry with materialdried over sodium sulfate
11. filtrationfiltered
12. concentrationconcentrated under reduced pressure
13. customto provide the crude aldehyde, which
14. filtrationwas purified by filtration over SiO2 (dichloromethane; TLC: ethyl acetate/heptane 1:2)

ORD record

ord-bcae39517ba245859cbebdc3c7d46d77

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08063042B2