Sodium borohydride → HCID 86652901, compound

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Reaction Conditions

Reaction Steps

To a two-neck flask with a nitrogen inlet, compound 9 (5.2 g, 18 mmol, 1 equiv) was dissolved in 200 mL methanol/THF (10/1). The solution was cooled to −10° C. in a salted ice bath, followed by the addition of sodium borohydride (0.8 g, 21 mmol, 1.2 equiv). The mixture was stirred at 0° C. for 20 min, then allowed to warm to rt and stirred for an additional 20 min. The mixture was concentrated under vacuum, cooled to 0° C. and acidified with diluted HCl solution. The aqueous solution was extracted with ethyl acetate. The combined organic extracts were washed with brine (200 mL) and dried over MgSO4. After filtration the solvent was removed under vacuum to afford crude product as a yellowish solid. This was chromatographed on a silica gel column (eluent: 0% to 5% of methanol in CH2Cl2) to give 10 as a white solid (4.95 g, yield: 95%). 1H NMR δ=7.10 (d, J=1.8, 1H), 6.97 (dd, J1=1.8, J2=8, 1H), 6.93 (d, J=8, 1H), 4.78 (d, J=2.3, 2H, —OCH2C≡CH), 4.64 (d, J=5.8, 2H, —CH2OH), 4.34 (t, J=6.6, 2H, —OCH2CH2Br), 3.66 (t, J=6.6, 2H, —OCH2CH2Br), 2.51 (t, J=2.3, 1H, —C≡CH), 1.68 (t, J=5.8, 1H, —CH2OH). 13C NMR δ=147.90, 145.60, 135.34, 121.32, 115.46, 114.92, 78.78 (—C≡CH), 76.12 (—C≡CH), 70.54 (—CH2OH), 66.28 (—OCH2CH2Br), 57.38 (—OCH2C≡CH), 29.32 (—OCH2CH2Br). HRMS calculated for C12H11BrO3 (M+Na+), 354.9807; found, 354.9810.

Provenance & Evidence