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0 °C

(2S)-4-(1-hydroxy-2-naphthyl)-1,2-butanediol (3.50 g, 15.1 mmol) is dissolved in hydrogen bromide (30 wt. % in acetic acid, 100 mL) and the reaction mixture is stirred at 0° C. for 2 h. The reaction mixture is quenched by the addition of water (500 mL) and extracted with ethyl acetate (3×200 mL). The combined organic extracts are washed with water (3×200 mL), aqueous sodium chloride (300 mL), dried (magnesium sulfate), and the solvent is removed in vacuo to provide a crude oil. The residue is dissolved in methanol (100 mL) and the resulting solution is slowly added to a solution of aqueous sodium hydroxide (2.5 M, 150 mL) in water (350 mL) and the reaction mixture is allowed to stir at 0° C. for 30 min. The reaction mixture is quenched by the addition of aqueous hydrogen chloride (1.0 M, 500 mL) and extracted with ethyl acetate (3×200 mL). The combined organic extracts are washed with water (2×200 mL), aqueous sodium chloride (300 mL), dried (magnesium sulfate), and the solvent is removed in vacuo to provide a crude oil. Purification by flash column chromatography (silica, ethyl acetate:hexanes 1:1) provides 5.38 g (70%, 50% ee) of (2R)-3,4-dihydro-2H-benzo[h]chromen-2-ylmethanol as a colorless oil. [α]D25=−51.23 (c 11.58 in chloroform, 50% ee); Rf=0.52 (silica, ethyl acetate:hexanes 1:1); Anal. Calcd. for C14H14O2.0.25H2O: C, 76.86; H, 6.68. Found: C, 76.47; H, 6.38.

1. customThe reaction mixture is quenched by the addition of water (500 mL)
2. extractionextracted with ethyl acetate (3×200 mL)
3. washThe combined organic extracts are washed with water (3×200 mL), aqueous sodium chloride (300 mL)
4. dry with materialdried (magnesium sulfate)
5. customthe solvent is removed in vacuo
6. customto provide a crude oil
7. stirringto stir at 0° C. for 30 min
8. customThe reaction mixture is quenched by the addition of aqueous hydrogen chloride (1.0 M, 500 mL)
9. extractionextracted with ethyl acetate (3×200 mL)
10. washThe combined organic extracts are washed with water (2×200 mL), aqueous sodium chloride (300 mL)
11. dry with materialdried (magnesium sulfate)
12. customthe solvent is removed in vacuo
13. customto provide a crude oil
14. customPurification by flash column chromatography (silica, ethyl acetate:hexanes 1:1)