Water → 4a'-methyl-(4'H,5'H,7'H)-spiro[1,3-dithiolane-2,2'-naphthalen]-5'(6'H)-one

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Reaction Steps

To a solution of Wieland-Miescher ketone (5.87 g, 33.0 mmol) in glacial acetic acid (40 mL) was added p-toluenesulfonic acid (2.94 g) followed by dropwise addition of 1,2-ethanedithiol over a 1 hour period. The reaction mixture was stirred at room temperature for another 4 hours, poured into 30 mL water, and stirred for 15 minutes. The white solid was filtered off, washed successively with water, diluted with NaHCO3 solution and water, and then dried to yield thioketal 239 (7.33 g, 87.3%) as a white solid. 1H NMR (CDCl3) δ 1.50-2.70 (m, 10H), 3.20-3.40 (m, 4H), 5.67 (s, 1H); 13C NMR (CDCl3) 212.92, 141.23, 128.04, 64.81, 49.43, 40.11, 39.62, 37.92, 37.57, 30.81, 30.69, 24.73, 24.57.

Provenance & Evidence