Chromium trioxide diethyl ether

To which a solution of manganese sulfate (15 g), 3.1 g of chromium trioxide, 72 ml of water and 3.5 ml of sulfuric acid was added. After stirring for 3.5 hours at 3°C, extracted with diethyl ether. The organic layer was washed with water, dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel using ethyl acetate-benzene (1 1) as eluent to give 2.35 g of the title compound. 

Iodo-4-nit.rot.olucne (0.19 mol) was dissolved in a mixture of 380 ml acetic acid, 190 ml acetic anhydride, and 112 ml 18 M sulfuric acid previously cooled in an ice bath. Chromium trioxide (0.57 mol) was then added portionwise for over 30 minutes, which was accompanied by a temperature increase to 90°C. The thick suspension was cooled 30 minutes in an ice bath, poured over ice (2 kg), and a precipitate isolated by filtration. The solid was washed with 800 ml methyl alcohol, then 200 ml diethyl ether, dried, and the product isolated in 94% yield. 

A solution of 10.0 g (1(X) mmol) of chromium trioxide in 28 mL of water and 9 mL of concentrated sulfuric acid is added at 0 - 5 C to a solution of 12.6 g (100 mmol) of a mixture of endo- and exo-5.6c in 65 mL of acetone. The mixture is stirred for 1.5 h at 0 °C, 120 mL water are added and the mixture is extracted with diethyl ether. The organic layer is washed with saturated sodium hydrogen carbonate solution and brine, dried with magnesium sulfate and concentrated in vacuo to give 10.1 g (80%) of a yellow oil. 

Chromium trioxide and certain other chromium(VI) compounds are useful as strong oxidizing agents in the laboratory, but appropriate precautionary measures should be taken when conducting these reactions. Chromium trioxide has been reported to react violently with a variety of substances, including readily oxidized organic compounds such as acetone, acetaldehyde, methanol, ethanol, diethyl ether, ethyl acetate, acetic acid, and DMF, and violent reactions may also occur on reaction with alkali metals, gaseous ammonia, phosphorus, and selenium. 

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