反应详情

A solution of compound 4 (6.12 g, 14.5 mmol) in MeOH (100 mL) was treated with PPTS (0.36 g, 1.43 mmol) at room temperature for overnight. After concentration, the residue was purified by silica gel column chromatography with 20% EtOAc in hexanes to give 3.84 g of product 5 (11.3 mmol, 78%); 1H NMR (CDCl3) δ 7.80˜7.66 (m, 4H), 7.49˜7.35 (m, 6H), 4.33 (t, J=1.9 Hz, 1H), 3.60 (t, J=6.0 Hz, 2H), 2.40 (tt, J=2.2, 6.1 Hz, 2H) 1.05 (s, 9H).

1. concentrationAfter concentration
2. customthe residue was purified by silica gel column chromatography with 20% EtOAc in hexanes