Oxygen → 2-Methyl-3-buten-2-ol

Participants

Reaction Steps

A mixture of 1.0 g (14.3 mmol) of 2-methyl-2-butene and 500 mg. of photosensitizing resin in 150 ml of methanol was irradiated as described above. The volume of oxygen uptake was measured. To the solution was added sodium borohydride, and after 5 min. the solution was extracted with ether (20 ml.) The ether solution was analyzed by gas chromatography to give 3-methylbut-3-ene-2-ol and 2-methylbut-3-ene-2-ol, in a 50:50 ratio, within experimental error. The ratio of these two products is the same as that observed when rose bengal or methylene blue are dissolved in methanol. Hence the same intermediate, singlet oxygen is involved in both processes. Radical oxidation leads to different products.

Provenance & Evidence