[CH2:1]([C:4]1[C:5]([O:16][CH3:17])=[C:6]([CH:11]=[C:12]([Cl:15])[C:13]=1[NH2:14])[C:7]([O:9][CH3:10])=[O:8])[CH:2]=[CH2:3].C1C[O:21]CC1>C1COCC1.COCCOCCOC>[OH:21][CH2:3][CH2:2][CH2:1][C:4]1[C:5]([O:16][CH3:17])=[C:6]([CH:11]=[C:12]([Cl:15])[C:13]=1[NH2:14])[C:7]([O:9][CH3:10])=[O:8]A mixture of a 1M solution of BH3 in THF(8 ml) and the compound of step 3 above (2 g) in THF-diglyme (10 ml/16 ml) is stirred under N2 for 30 minutes at 20° C. Me3NO.2H2O (2.2 g) is added to the mixture and refluxed in a preheated oil bath allowing the THF to evaporate, followed by refluxing the mixture for one hour. The mixture is cooled to 20° C., partitioned between CHCl3 and sat'd aqueous NaHCO3, and stirred for 30 minutes. The organic layer is separated, washed with H2O, dried (MgSO4), evaporated and the residue is chromatographed on silica gel affording the desired product as a solid which is determined to be the correct product by NMR.
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