[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([CH:16]=[CH2:17])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].B.C1C[O:22]CC1.O.C([O-])([O-])=O.C([O-])([O-])=O.OO.OO.OO.[Na+].[Na+].[Na+].[Na+]>C1COCC1>[OH:22][CH2:17][CH2:16][C:12]1[C:9]2[C:10]([CH3:11])=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[O:7][C:8]=2[CH:15]=[CH:14][CH:13]=1To a solution of 0.35 g (1.5 mmol) of 3-methyl-4-vinyl-1-benzofuran-2-carboxylate (Example 87, Step 1) in 3 mL of THF, cooled in an ice bath, was added 1 mL (1 mmol) of borane-THF complex (1.0M solution in THF). The reaction was stirred at room temperature for 2 hours. The reaction was cooled in an ice bath and 1.5 mL of water was added. Next 0.61 g of sodium percarbonate was added in one portion. The reaction was heated at ˜50° C. for 1 hour, then cooled to room temperature. Water was added and the resulting mixture was extracted with ethyl acetate. The organic layer washed with water and brine, dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was chromatographed on silica gel eluting with hexane/ethyl acetate (2:1) to provide 0.20 g of ethyl 4-(2-hydroxyethyl)-3-methyl-1-benzofuran-2-carboxylate. Yield 54%. m.p. 88-90° C.; MS 249.1 (M+H)+.
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