[Si]([O:8][C@@H:9]([C@@H:11]1[C@@H:14]([C@@H:15]([CH3:25])[C:16](=[O:24])[CH2:17][C:18]([O:20][CH2:21][CH:22]=[CH2:23])=[O:19])[NH:13][C:12]1=[O:26])[CH3:10])(C(C)(C)C)(C)C.Cl.OP([O-])([O-])=O.[K+].[K+]>CO.C(OC(=O)C)C.O>[OH:8][C@@H:9]([C@@H:11]1[C@@H:14]([C@@H:15]([CH3:25])[C:16](=[O:24])[CH2:17][C:18]([O:20][CH2:21][CH:22]=[CH2:23])=[O:19])[NH:13][C:12]1=[O:26])[CH3:10]The keto ester 2 (1.047 g, 2.73 mmol) in methanol (12.3 ml) was treated with 6N HCl (1.37 ml, 8.22 mmol, 3 eg) and stirred 1 hour at room temperature. The solution was treated with 1M K2HPO4 (8.2 ml) and stirred a few minutes, then diluted with ethylacetate and water. The organic layer was separated, washed with 5% NaHCO3 and brine, dried with magnesium sulfate, filtered, and evaporated under vacuum to give the product 3 (0.653 g, 89%) as a clear oil.
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