Potassium Hydroxide → 1,4,5,6-Tetrachloro-7,7-dimethoxy-bicyclo[2.2.1]hept-5-ene-2,3-diol

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Reaction Steps

Potassium hydroxide (112 g, 1.20 mol) in water (1 L) was treated with 1,7,8,9-tetrachloro-10,10-dimethoxy-3,5-dioxa-tricyclo[5.2.1.02,6]dec-8-en-4-one (358.3 g, 1.23 mol) in THF (500 mL) via addition funnel, producing a slight exotherm. The reddish solution was stirred overnight at room temperature. By morning, the solution became a murky dispersion, which was diluted with water (500 mL), and 12N HCl (20 mL) to pH 10. The product was extracted with EtOAc (1×1000 mL) and ether (1×500 mL). The combined organic layers were washed with 1N HCl (1×300 mL), water (1×300 mL), saturated aqueous NaHCO3 solution (1×300 mL) and saturated aqueous NaCl solution (1×300 mL), dried over Na2SO4, filtered and concentrated to give a light brown solid (310 g, 78%). (TLC 40% EtOAc/hexanes Rf 0.55); 1H NMR (400 MHz, CDCl3) δ 4.46 (s, 2H), 3.54 (s, 3H), 3.51 (s, 3H); GCMS m/z 322 (M)+, 287, 289 (M-Cl)+; mp 160–162° C.; Anal. Calcd for C9H10Cl4O4: C, 33.37; H, 3.11. Found C, 33.34; H, 3.16.

Provenance & Evidence