A solution of (6-benzenesulfonyl-1-hydroxy-1,2,3,4-tetrahydro-naphthalen-1-yl)-acetic acid methyl ester (1.28 g, 3.42 mmol) and para-toluenesulfonic acid (0.50 g) in 250 mL of benzene was refluxed for 2 hours using a Dean-Stark trap. The reaction mixture was cooled and poured into 500 mL of EtOAc, and this organic phase was washed with water, saturated NaHCO3, and dried (MgSO4). Evaporation under reduced pressure gave a dark oil that was purified by elution on silica gel (hexanes:EtOAc 7:3) to yield 0.991 g (2.78 mmol, 81.2% of a white crystalline solid. MS: 357 (M+H)+.
