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

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence