p-Toluenesulfonic acid → Ethyl ({[2-(1,3-benzodioxol-5-yl)-5,5-dimethyl-1,3-dioxan-2-yl]methyl}thio)acetate

Participants

Reaction Steps

Ethyl {[2-(1,3-benzodioxol-5-yl)-2-oxoethyl]thio}acetate (Method 11) (15.8 g, 0.056 mol) was dissolved in benzene (500 mL) and 2,2-dimethyl-1,3-propanediol (46.6 g, 0.45 mol) and p-toluene sulfonic acid (cat., 500 mg) were added. The mixture was stirred at reflux in a Dean-Stark apparatus for two hours, given room temperature and concentrated under reduced pressure. The resulting white solid was dissolved in CH2Cl2 (500 mL) and washed twice with water (300 mL) and brine (300 mL). The organic layer was dried (MgSO4) and concentrated under reduced pressure. The crude oil was purified by flash-chromatography (heptane:EtOAc 4:1) to afford the desired product.

Provenance & Evidence