4-Toluenesulfonyl chloride → [8-Methyl-2,3-dihydrofuro[3,2-f][1,4]benzodioxin-2-yl]methyl 4-methylbenzenesulfonate

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Reaction Steps

To a solution of 0.20 g (0.90 mmole) of [(2S)-8-methyl-2,3-dihydrofuro[3,2-f][1,4]benzodioxin-2-yl]methanol in 5.0 mL of pyridine was added 1.0 g (5.2 mmole) of p-toluenesulfonyl chloride. The mixture was stirred at room temperature under nitrogen for 15 hours. The solvent was then removed in vacuum and replaced with 200 mL of methylene chloride. The solution was washed with 100 mL portions of 2 N aqueous HCl, saturated aqueous sodium bicarbonate and saturated brine, dried over magnesium sulfate, filtered and concentrated in vacuum to a brown residue. The residue was column chromatographed on silica gel with 1:1 methylene chloride/hexane as eluant and the product fractions combined and concentrated in vacuum to give 0.28 g of the (R)-enantiomer of the title compound as a pale yellow oil. 1H-NMR (CDCl3): doublet 7.79 δ (2H); doublet 7.30 δ (2H); doublet 6.86 δ (1H); doublet 6.68 δ (1H); singlet 6.29 δ (1H); multiplet 4.48 δ (1H); multiplet 4.26 δ (3H); doublet of doublets 4.06 δ (1H); singlet 2.43 δ (3H); singlet 2.41 δ (3H).

Provenance & Evidence