[CH2:1]([O:3][C:4](=[O:33])[CH:5]([C:13]1[C:18]([N+:19]([O-])=O)=[CH:17][CH:16]=[C:15]([O:22][CH:23]2[CH2:28][CH2:27][N:26]([CH2:29][CH2:30][O:31][CH3:32])[CH2:25][CH2:24]2)[N:14]=1)C(OC(C)(C)C)=O)[CH3:2]>C(O)(C(F)(F)F)=O>[CH2:1]([O:3][C:4](=[O:33])[CH2:5][C:13]1[C:18]([NH2:19])=[CH:17][CH:16]=[C:15]([O:22][CH:23]2[CH2:24][CH2:25][N:26]([CH2:29][CH2:30][O:31][CH3:32])[CH2:27][CH2:28]2)[N:14]=1)[CH3:2]A mixture of 3 (0.856 mmol) in TFA (15 mL) was agitated at room temperature for 20 min. LCMS indicated a mixture of ˜1:1 of the tButyl cleavage/decarboxylation to tButyl and Ethyl cleavage/decarboxylation. The TFA was removed in vacuo. The resulting oil was put up in ethyl acetate and washed with sodium bicarbonate (aq., satd.), brine then dried over MgSO4 and concentrated in vacuo. The free based material (4) was dissolved in ethanol (20 mL) and hydrogenated in the presence of 10% Pd/C (30 mg) at 20 psi on the Parr shaker for 1 hour. The suspension was filtered over celite and concentrated in vacuo yielding an orange-yellow oil (253 mg, 87.4%).
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