Methanol → ethyl [(1S)-5-(2-hydroxyethoxy)-2,3-dihydro-1H-inden-1-yl]acetate

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Reaktionsschritte

Ethyl [(1S)-5-(2,2-diethoxyethoxy)-2,3-dihydro-1H-inden-1-yl]acetate (Example 248, 849 mg, 2.52 mmol) was dissolved in a mixture of acetone (60 mL) and HCl (30 mL of a 2N aqueous solution). The reaction mixture was stirred at rt for 18 h, then neutralized (pH 7) by addition of a saturated solution of NaHCO3. The aqueous phase was extracted with CH2Cl2, and the combined organic phases were dried (Na2SO4), filtered, and concentrated under reduced pressure. To a solution of the crude aldehyde in CH2Cl2 (30 mL) were then added NaBH4 (69 mg, 1.82 mmol) and MeOH (5 mL) were added. After stirring for 5 h at rt, the reaction mixture was washed with a saturated solution of NaHCO3, the organic phase was dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by a plug of silica gel (eluent: EtOAc) to provide the product (264 mg, 38%). 1H NMR (400 MHz, CDCl3) δ 1.21 (t, 3H) 1.65-1.71 (m, 1H), 2.29-2.36 (m, 2H), 2.63 (dd, 1H) 2.75-2.83 (m, 2H), 3.43-3.45 (m, 1H), 3.86 (t, 2H), 3.98 (t, 2H), 4.09 (q, 2H), 6.63 (d, 1H), 6.69 (s, 1H) 6.99 (d, 1H).

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