[O:1]=[O+][O-].[CH2:4]([O:7][C:8]1[CH:15]=[CH:14][CH:13]=[CH:12][C:9]=1[CH2:10][OH:11])[CH:5]=C.[BH4-].[Na+]>CO>[OH:1][CH2:5][CH2:4][O:7][C:8]1[CH:15]=[CH:14][CH:13]=[CH:12][C:9]=1[CH2:10][OH:11]Ozone was bubbled through a -78° C. dry methanol solution of 2-(allyloxy)benzyl alcohol (LaChapelle et al Tetrahedron, 44(16), 5033-5044 (1988)) (7.0 g, 43 mmol) for 13 minutes, checking the reaction TLC profile every 2 minutes for complete disappearance of the starting olefin (Rf=0.8, 75% EtOAc/hexane). The reaction mixture was purged with nitrogen, NaBH4 (9.7 g, 0.25 mol) was added and the reaction temperature brought to 0° C. After 30 minutes, the reaction was warmed to room temperature, concentrated, diluted with ether, washed with water, brine, dried and concentrated to a residue. The residue was eluted through a pad of silica with EtOAc/hexanes (gradient elution 25%-75% EtOAC). Evaporation of the eluting solvent gave the diol, 2-(2'-hydroxyethoxy)-benzyl alcohol, (4.8 g, 67%) as an oil. MS: MW=168; observed 168, FD, CHCl3).
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