Reaction Steps
To a solution of methyl(2S)-2-(tert-butoxy)-2-[(22S)-18-fluoro-4,22,28-trimethyl-21,27-dioxa-1,7,34-triazahexacyclo[26.2.2.16,9.110,14.02,7.015,20]tetratriaconta-2,4,6(34),8,10(33),11,13,15(20),16,18-decaen-3-yl]acetate (11 mg, 0.017 mmol, 1 equiv) in 9:1 MeOH:water (1.1 mL) was added LiOH.H2O (28 mg, 0.671 mmol, 40 equiv). The reaction was heated to 70° C. for 1 h. Upon cooling to ambient temperature, the reaction was filtered and purified via preparative LC/MS with the following conditions: Column: XBridge C18, 19×200 mm, 5-μm particles; Mobile Phase A: 5:95 acetonitrile:water with 10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with 10-mM ammonium acetate; Gradient: 45-85% B over 15 minutes, then a 5-minute hold at 100% B; Flow: 20 mL/min. Product isolated (7.2 mg, 77%). 1H NMR (500 MHz, DMSO-d6) δ 7.84 (d, J=7.6 Hz, 1H), 7.76 (d, J=6.1 Hz, 2H), 7.28 (t, J=7.6 Hz, 1H), 7.11 (t, J=7.6 Hz, 1H), 7.06 (s, 1H), 7.03 (d, J=7.3 Hz, 1H), 6.89 (d, J=11.6 Hz, 1H), 6.62 (t, J=8.1 Hz, 1H), 5.90-5.80 (m, 1H), 5.68 (br. s., 1H), 5.54 (d, J=15.6 Hz, 1H), 4.44 (br. s., 1H), 3.80-3.65 (m, 3H), 3.39 (d, J=11.3 Hz, 1H), 2.87 (d, J=8.5 Hz, 1H), 2.37 (d, J=8.2 Hz, 1H), 2.33-2.29 (m, 1H), 2.28 (br. s., 3H), 2.08-1.98 (m, 1H), 1.76-1.58 (m, 2H), 1.52-1.40 (m, 2H), 1.01 (s, 3H), 0.94 (s, 9H), 0.83 (d, J=5.8 Hz, 3H); LCMS (ESI, M+1): 642.5.
