Dimethyl Sulfoxide → Benzyl 4-formylbicyclo[2.2.2]octane-1-carboxylate

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Reaction Steps

Oxalyl chloride (COCl)2 (16.5 ml, 188 mmol) in methylene chloride (150 ml) is cooled to −63°. DMSO (18 ml, 362 mmol) is then added dropwise. The resulting mixture is stirred for 30 minutes and then a mixture of 4-hydroxymethylbicyclo[2.2.2]octane-1-carboxylic acid benzyl ester (XVIII, Example 93, 34.5 g, 125 mmol) in methylene chloride (100 ml) is added over 15 minutes. After another 30 minutes, triethylethylamine (70 ml, 502 mmol) in methylene chloride (30 ml) is added over 25 minutes. (Extra Caution: extremely exothermic reaction when the first equivalent of the triethylamine is added.) The reaction mixture then stirred for another 45 minutes and the cooling bath is removed and allowed to warm up to 20-25°. Water (50 ml) is added and the organic layer is separated, dried over anhydrous sodium sulfate and concentrated to give the title compound, NMR (400 MHz, CDCl3) δ 9.51, 7.32, 5.11, 1.88 and 1.64.

Provenance & Evidence