Cyclopentadiene → (2-Oxa-3-azabicyclo[2.2.1]hept-5-en-3-yl)-phenylmethanone

Beteiligte Stoffe

Reaktionsschritte

Tetra-n-butylammonium periodate (17.3 g, 39.9 mmol) was added to a solution of freshly cracked cyclopentadiene (4.00 g, 60.6 mmol) in dichloromethane (150 cm3). Benzohydroxamic acid (5.50 g, 40.1 mmol) was then added portionwise over 5 minutes and the solution was stirred overnight at room temperature. Upon completion of reaction, the organic solution was washed successively with sodium thiosulfate (10% aq. soln., 2×400 cm3) and sodium hydrogen carbonate (sat'd. aq., 500 cm3), then dried over anhydrous magnesium sulfate, filtered and concentrated to give a crude black oil. Flash chromatography (SiO2, 40% ethyl acetate in petrol) gave the bicyclic adduct 7 (6.23 g, 31.0 mmol, 78%) as a light brown oil, which solidified upon standing at room temperature; δH (250 MHz, CDCl3) 7.75 (2H, m, ArH), 7.52–7.37 (3H, m, ArH), 6.50 (1H, m, CH═CH), 6.37 (1H, m, CH═CH), 5.35 (1H, m, CHNBz), 5.28 (1H, m, CHON), 2.13 (1H, dt, J 8.6 & 1.9 Hz, CHH), 1.84 (1H, m, CHH).

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