dimethyl (2S,3S)-2,3-dihydroxybutanedioate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In this example 50.0 g (0.28 mole) of dimethyl D-tartrate and 39.5 g (0.28 mole) of 2-chlorobenzaldehyde were refluxed for 48 hours in 500 ml of toluene in the presence of 0.2 g of p-toluenesulfonic acid. Water was azeotroped off with the aid of a Dean-Stark trap. The reaction mixture was concentrated by evaporation under reduced pressure to afford 50.8 g (60% yield) of the title compound as a solid which was washed with hexane and ether. Water was azeotroped off with the aid of a Dean-Stark trap The reaction mixture was concentrated by evaporation under reduced pressure