methyl 2-acetoxy-3-(7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazol-5-yl)acrylate → (R)-Methyl 2-acetoxy-3-(7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazol-5-yl)propanoate

Participants

Reaction Steps

To a solution of methyl 2-acetoxy-3-(7-methyl-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazol-5-yl)acrylate (825 mg, 2.04 mmol) in degassed (by bubbling nitrogen) dichloromethane (20.00 mL) under nitrogen was added solid (−)-1,2-bis-((2R,5R)-2,5-diethylphospholano)benzene-(cyclooctadiene)rhodium(I) tetrafluoroborate (100.00 mg), all at once. The reaction was placed under a hydrogen atmosphere (55 psi), and shaken for 6 h. The reaction was concentrated and purified by column chromatography (25% ethyl acetate/hexanes) to give 700 mg (84%) as a colorless oil. 1H-NMR (CDCl3, 500 MHz) δ −0.03 (s, 9H), 0.94 (t, J=8.2, 2H), 2.07 (s, 3H), 2.61 (s, 3H), 3.11 (dd, J=14.3, 8.9, 1H), 3.20 (dd, J=14.3, 4.6, 1H), 3.64 (t, J=8.5, 2H), 3.72 (s, 3H), 5.26 (dd, J=8.5, 4.6, 1H), 5.72 (s, 2H), 6.93 (s, 1H), 7.33 (s, 1H), 8.02 (s, 1H).

Provenance & Evidence