B.CSC.[C:5]([CH2:8][C:9]1[C:10]([Cl:18])=[C:11]([CH:15]=[CH:16][CH:17]=1)[C:12](O)=[O:13])(O)=[O:6]>C1COCC1>[Cl:18][C:10]1[C:11]([CH2:12][OH:13])=[CH:15][CH:16]=[CH:17][C:9]=1[CH2:8][CH2:5][OH:6]A solution of borane-methyl sulfide complex (2M in THF, 20 mL) was added portionwise over 5 minutes to a suspension of 3-(carboxymethyl)-2-chlorobenzoic acid (example 80, step b) (4.11 g) in dry THF (100 mL) at room temperature. The resulting effervescing suspension was stirred at room temperature for 30 minutes, then heated to reflux for 60 minutes, and allowed to cool to room temperature overnight. The mixture was quenched by the portionwise addition of methanol (15 mL) over 15 minutes. The mixture was diluted further with methanol to give a solution, which was then concentrated in vacuo to give a syrup. The syrup was purified by flash chromatography on silica eluted with 2% methanol in dichloromethane to the afford the crude subtitled compound as a white solid. Yield 1.44 g.
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