Reaction Steps
To a solution of (2S)-2-(tert-butoxy)-2-[(20S)-14,16-difluoro-4,20,26-trimethyl-11,19,25-trioxa-1,5,7,8-tetraazapentacyclo[24.2.2.16,9.02,7.013,18]hentriaconta-2,4,6(31),8,13,15,17,22-octaen-3-yl]acetic acid (0.020 g, 0.032 mmol) in ethanol (0.5 mL) were added Hoveyda-Grubbs catalyst 2nd generation (3.99 mg, 6.36 μmol) and sodium borohydride (6.02 mg, 0.159 mmol) and the mixture was stirred at rt. After 30 min, the mixture was quenched with water and the product was extracted with EtOAc. The organic phase was dried (Na2SO4), filtered and concentrated. The crude material was purified via preparative HPLC to afford (2S)-2-(tert-Butoxy)-2-[(20S)-14,16-difluoro-4,20,26-trimethyl-11,19,25-trioxa-1,5,7,8-tetraazapentacyclo[24.2.2.16,9.02,7.013,18]hentriaconta-2,4,6(31),8,13,15,17-heptaen-3-yl]acetic acid (3.9 mg, 12.83% yield). 1H NMR (500 MHz, DMSO-d6) δ: 6.92 (d, J=11.7 Hz, 1H), 6.77 (t, J=9.0 Hz, 1H), 6.42 (s, 1H), 4.83-4.54 (m, 4H), 4.49-4.24 (m, 2H), 3.61 (dd, J=10.5, 4.6 Hz, 2H), 3.37 (br. s., 2H), 2.59 (d, J=9.9 Hz, 1H), 2.33-1.97 (m, 4H), 1.93 (br. s., 1H), 1.88-1.41 (m, 9H), 1.31-1.06 (m, 15H). LCMS (M+H) calcd for C33H45F2N4O6: 631.33. found: 631.4.
