[Si:1]([O:18][CH2:19][C:20]([C:23]1[CH:27]=[C:26]([NH:28][C:29]([NH:31][C@@H:32]2[C:41]3[C:36](=[CH:37][CH:38]=[CH:39][CH:40]=3)[C@H:35]([O:42][C:43]3[CH:44]=[CH:45][C:46]4[N:47]([C:49]([N:52]5[CH2:57][CH2:56][CH2:55][CH2:54][C@@H:53]5[CH3:58])=[N:50][N:51]=4)[CH:48]=3)[CH2:34][CH2:33]2)=[O:30])[N:25]([C:59]2[CH:64]=[CH:63][CH:62]=[C:61]([O:65][CH2:66][CH2:67][O:68]C3CCCCO3)[CH:60]=2)[N:24]=1)([CH3:22])[CH3:21])([C:14]([CH3:17])([CH3:16])[CH3:15])([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>CO>[Si:1]([O:18][CH2:19][C:20]([C:23]1[CH:27]=[C:26]([NH:28][C:29]([NH:31][C@@H:32]2[C:41]3[C:36](=[CH:37][CH:38]=[CH:39][CH:40]=3)[C@H:35]([O:42][C:43]3[CH:44]=[CH:45][C:46]4[N:47]([C:49]([N:52]5[CH2:57][CH2:56][CH2:55][CH2:54][C@@H:53]5[CH3:58])=[N:50][N:51]=4)[CH:48]=3)[CH2:34][CH2:33]2)=[O:30])[N:25]([C:59]2[CH:64]=[CH:63][CH:62]=[C:61]([O:65][CH2:66][CH2:67][OH:68])[CH:60]=2)[N:24]=1)([CH3:21])[CH3:22])([C:14]([CH3:15])([CH3:17])[CH3:16])([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1A solution of Intermediate 153g (317 mg, 0.31 mmol) in MeOH (3.1 mL) was treated with pyridinium para-toluenesulfonate (235 mg, 0.93 mmol) and the mixture was stirred at 45° C. for 19 h. The cooled solution was concentrated in vacuo, and the residue was partitioned between DCM and a saturated aqueous sodium bicarbonate solution. The phases were separated and the aqueous layer was extracted with DCM (×2). The combined organic phase was washed with water, a saturated aqueous sodium bicarbonate solution, and brine, dried (Na2SO4) and concentrated in vacuo to a cream coloured foam. The foam was purified by FCC, using 0-10% MeOH in DCM, to give the title compound as a colourless glass (217 mg, 75%). LCMS (Method 3): Rt 5.06 min, m/z 933.7 [MH+].
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