反应详情

A solution of 5 (0.50 g, 1.377 mmol, 1.0 equiv) and 20% Pd—C (55% H2O) (0.05 g) in 1:1 EtOH/EtOAc (30 mL) was hydrogenated at 30 psi H2 for 4.25 hr. LCMS showed some 5 remained along with A and a small amount of over-reduction products. The mixture was hydrogenated at 20 psi H2 for 2.75 hr (LCMS showed ˜2% 5 remained). The mixture was filtered through Celite, and the Celite layer was washed with 1:1 EtOH/EtOAc (30 mL). The filtrate was concentrated under reduced pressure to give a brown oil. The crude product was absorbed onto silica gel using DCM and dry-loaded on a column of silica gel (10 g) packed in hexanes. The column was eluted with hexanes (100 mL), 5% EtOAc/hexanes (100 mL) and 10% EtOAc/heptanes (200 mL). Product fractions were concentrated under reduced pressure to give 0.40 g (105%—residual solvent present) of A as a colorless, viscous oil.

1. filtrationThe mixture was filtered through Celite
2. washthe Celite layer was washed with 1:1 EtOH/EtOAc (30 mL)
3. concentrationThe filtrate was concentrated under reduced pressure
4. customto give a brown oil
5. customThe crude product was absorbed onto silica gel
6. washThe column was eluted with hexanes (100 mL), 5% EtOAc/hexanes (100 mL) and 10% EtOAc/heptanes (200 mL)
7. concentrationProduct fractions were concentrated under reduced pressure
8. customto give 0.40 g (105%—residual solvent present) of A as a colorless, viscous oil