Reaction Steps
A mixture of (S)-ethyl 2-(7-(4-(allyloxy)-4-methylpiperidin-1-yl)-2-(((2-(but-3-en-1-yl)benzyl)oxy)methyl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate (55 mg, 0.089 mmol) and (1,3-dimesitylimidazolidin-2-ylidene)(2-isopropoxybenzylidene)ruthenium(VI) chloride (5.57 mg, 8.89 μmol) in ClCH2CH2Cl (60 mL) was refluxed for 2 h. It was then concentrated and the residue was dissolved in MeOH (5 mL). Sodium borohydride (3.36 mg, 0.089 mmol) was added and the reaction was stirred at rt for 1 h. It was then quenched with water, extracted with EtOAc. The organic layer was dried over MgSO4, filtered and concentrated to obtain an oil, which was then purify by biotage, eluting with 20% EtOAc/hexane to obtain ethyl (2S)-2-(tert-butoxy)-2-{4,25-dimethyl-11,24-dioxa-1,5,7,8-tetraazapentacyclo[23.2.2.16,9.02,7.013,18]triaconta-2,4,6(30),8,13(18),14,16-heptaen-3-yl}acetate (37 mg, 70%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 7.38-7.15 (m, 4H), 6.57 (s, 1H), 6.07 (s, 1H), 4.82-4.69 (m, 4H), 4.59 (t, J=11.2 Hz, 1H), 4.28-4.12 (m, 2H), 3.91 (t, J=10.9 Hz, 1H), 3.44 (d, J=7.3 Hz, 2H), 3.05 (d, J=11.3 Hz, 1H), 2.89 (dd, J=14.2, 6.4 Hz, 1H), 2.78 (dd, J=13.8, 8.3 Hz, 2H), 2.63 (s, 3H), 2.03-1.89 (m, 2H), 1.88-1.64 (m, 8H), 1.28 (s, 3H), 1.25 (s, 9H), 1.24-1.19 (m, 3H). LCMS (M+1)=593.4.
