C(OC([N:8]1[CH2:13][CH2:12][CH:11]([CH2:14]CC(OC)=O)[CH2:10][CH2:9]1)=O)(C)(C)C.[CH3:20][Mg+].[Br-].CC[O:25][CH2:26][CH3:27]>>[OH:25][C:26]([CH3:27])([CH3:20])[CH2:14][CH:11]1[CH2:12][CH2:13][NH:8][CH2:9][CH2:10]1To a solution of 0.69 g (2.7 mmol) of 1-t-butoxycarbonyl-4-(methoxycarbonylethyl)piperidine (Example 22, Step 2) in 26 mL of ether at 0° C. was added dropwise 2.8 mL (8.4 mmol) of CH3MgBr (3 M in ether) and the reaction mixture was warmed slowly to rt. After stirring at rt for 6 h, the reaction was quenched by addition of 20 mL of sat'd NH4Cl solution and the mixture was stirred overnight. The mixture was extracted with ethyl acetate. The combined organic fractions were washed with sat'd NaCl solution, dried over MgSO4, filtered and the filtrate was concentrated. The residue was purified by chromatography (silica, hexanes-:ethyl acetate, 3:1) to give 0.5 g of the title compound.
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