Sodium borohydride → [4-(5-tert-Butyl-3-hydroxymethyl-4-isopropoxy-2-methyl-phenylethynyl)-phenyl]-acetic acid methyl ester
Reaction equation
[CH3:1][O:2][C:3](=[O:30])[CH2:4][C:5]1[CH:10]=[CH:9][C:8]([C:11]#[C:12][C:13]2[CH:18]=[C:17]([C:19]([CH3:22])([CH3:21])[CH3:20])[C:16]([O:23][CH:24]([CH3:26])[CH3:25])=[C:15]([CH:27]=[O:28])[C:14]=2[CH3:29])=[CH:7][CH:6]=1.[BH4-].[Na+]>CO>[CH3:1][O:2][C:3](=[O:30])[CH2:4][C:5]1[CH:6]=[CH:7][C:8]([C:11]#[C:12][C:13]2[CH:18]=[C:17]([C:19]([CH3:22])([CH3:21])[CH3:20])[C:16]([O:23][CH:24]([CH3:26])[CH3:25])=[C:15]([CH2:27][OH:28])[C:14]=2[CH3:29])=[CH:9][CH:10]=1Participants
4
Procedure
A stirred, cooled (ice bath) solution of [4-(5-tert-butyl-3-formyl-4-isopropoxy-2-methyl-phenylethynyl)-phenyl]-acetic acid methyl ester (Intermediate 142, 0.172 g, 0.42 mmol) in methanol (4 mL) was treated with sodium borohydride (0.02 g, 0.51 mmol) and the resulting reaction mixture was stirred for 1.5 h. The reaction mixture was quenched with water and extracted with diethyl ether. The organic phase was washed with water (×1) and brine (×1), dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to a residue that was subjected to flash column chromatography over silica gel (230–400 mesh) using 15–20% ethyl acetate in hexane as the eluent to afford the title product as a white solid (0.15 g, 88%).