p-Toluenesulfonic acid → Methyl-2-(R,S)-benzoyloxymethyl-1,3-dioxolane-4-(R)-carboxlate

Beteiligte Stoffe

Reaktionsschritte

To a solution of methyl-α,β-isopropylidene-D-glycerate (II) (Fluka: registry # 52373-72-5), (9.76 g, 60.9 mmol, 1 eq) and benzoyloxyacetaldehyde I (10 g, 60.9 mmol, 1 eq) in toluene (20 mL) at 80° C., p-toluenesulfonic acid (PTSA) (460 mg, 2.4 mmol, 4 mol %) was added. The reaction flask was kept under vacuum for one hour and a distillate was collected (80-85° C.) during this period of time. The residue was then cooled to room temperature (RT) and purified by column chromatography on silica gel, using hexanes/ethyl acetate as eluent to produce 13.2 g (81%) of the title compound as a mixture of cis and trans isomers in a ratio of 3:1.

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