反应详情

Dimethoxytrityl chloride (1.21 g, 3.57 mmol) was added to a solution of 8 (1.0 g, 2.94 mmol) in 17 ml of dry pyridine. The solution was stirred at room temperature for 2 h. and then poured into 250 ml of 5% sodium bicarbonate and extracted with 300 ml of ethyl acetate. The extract was dried over sodium sulfate and evaporated. The residue was purified by silica gel chromatography eluting with 50% hexane in ethyl acetate (1% triethylamine). The pure product fractions were pooled and evaporated affording a foam: 1.66 g (85%) yield; TLC (1:1, ethyl acetate/hexane), Rf=0.50; 1H NMR (CDCl3) 7.62 (1H, s, acetal CH), 7.43 (2H, d, J=8.2 Hz, aromatic), 7.33-6.81 (17H, aromatic), 3.92 (2H, t, J=6.4 Hz, CH2), 3.78 (6H, s, OCH3), 3.17 (1H, dd, J=3.3 and 9.4 Hz, CH), 3.03 (1H, t, J=7.7 Hz, CH), 2.37 (1H, m, CH), 2.10 (6H, s, acetyl), 1.81-1.38 (6multiplets, CH2). Anal. Calcd for C38H42O9: C, 71.01; H, 6.59. Found: C, 70.91; H, 6.42.

1. extractionextracted with 300 ml of ethyl acetate
2. dry with materialThe extract was dried over sodium sulfate
3. customevaporated
4. customThe residue was purified by silica gel chromatography
5. washeluting with 50% hexane in ethyl acetate (1% triethylamine)
6. customevaporated
7. customaffording a foam
8. custom1.66 g (85%) yield