B. Ethynyl p-tolyl sulfone. A 1-L, three-necked, round-bottomed flask equipped with a thermometer, a 500-mL addition funnel, a nitrogen inlet, and a Teflon-coated magnetic stirring bar is charged with p-tolyl 2-(trimethylsilyl)ethynyl sulfone (25.2 g, 0.1 mol) and 300 mL of reagent-grade methanol. After the mixture is <stirred> for <30 min>, a clear solution is obtained. In the addition funnel is placed 350 mL of an aqueous solution containing potassium carbonate (6.2 × 10−3 M) and potassium bicarbonate (6.2 × 10−3 M); this buffer is added at a rate to maintain the reaction <temperature> at <30°C> (Note 7) and (Note 8). The mixture is <diluted> with <water> (200 mL), and <extracted> with four 100-mL portions of <chloroform>. The combined organic phases are <washed> <3 times> with <water> (100 mL) and twice with brine (100 mL) prior to drying over <anhydrous sodium sulfate>. Removal of solvent under <reduced pressure> leaves a creamy white solid, which is <purified> by either <recrystallization> from ethyl acetate–petroleum ether or silica gel chromatography using 10% ethyl acetate in petroleum ether as eluant (Note 9). There is obtained 15.0 g (83%) of colorless crystals, mp 74–75°C (Note 10) and (Note 11).