[(3S)-6-chloro-2,3-dihydro-1,4-benzodioxin-3-yl]methanol

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

Procedure: 4-Toluenesulphonyl chloride (5.9 g) was added to a solution of (S)-7-chloro-1,4-benzodioxan-2-ylmethanol (6.0 g; prepared by the method described above) in pyridine (40 ml) and the mixture stirred for 4 hours. More 4-toluenesulphonyl chloride (250 mg) was added, stirring continued for 2 hours, then further 4-toluenesulphonyl chloride (250 mg) was added and stirring continued for 1 hour. The mixture was poured into water (200 ml) and extracted with ethyl acetate (2×200 ml). The combined extracts were washed with hydrochloric acid (2M; 2×200 ml), saturated aqueous sodium bicarbonate solution (2×200 ml) and brine (200 ml), then dried over magnesium sulphate. The solvent was removed in vacuo and the residue recrystallised from ether to give (R)-7-chloro-1,4-benzodioxan-2-ylmethyl 4-toluenesulphonate (7.00 g) m.p. 90-91° C. prepared by the method stirring continued for 2 hours stirring continued for 1 hour extracted with ethyl acetate (2×200 ml) The combined extracts were washed with hydrochloric acid (2M; 2×200 ml), saturated aqueous sodium bicarbonate solution (2×200 ml) and brine (200 ml) dried over magnesium sulphate The solvent was removed in vacuo the residue recrystallised from ether