反应详情

The intermediate from Step B (0.8 g, 1.6 mmol) was treated with 4-methoxy benzene (2 mL) and trifluoroacetic acid (15 mL). After stirring for 1.5 hours the solution was concentrated and the residue purified by silica gel chromatography using a hexanes/ethyl acetate gradient (containing 0.05% acetic acid) to give the title compounds as mixture of diastereomers. 1H NMR (400 MHz, CDCl3): selected data δ3.90 (s); 3.85 (s); 3.72-3.64 (m); 3.52-3.42 (m); 1.39 (d, J=6.8 Hz); 1.03 (d, J=7.0 Hz). LCMS1 3.34 min. (M+H)=377. LCMS1 3.57 min. (N+H)=377.

1. concentrationwas concentrated
2. customthe residue purified by silica gel chromatography
3. additiona hexanes/ethyl acetate gradient (containing 0.05% acetic acid)