反应详情

A solution of trityl chloride (3.44 g, 12.3 mmol) in methylene chloride (20 mL) is treated sequentially with 1,8-diazabicyclo[5.4.0]undec-7-ene (2.2 mL, 14.7 mmol, DBU) and 4-hydroxy-2-cyclopentenone (1.01 g, 10.0 mmol, in 5 mL of methylene chloride, prepared in example 1). The reaction is stirred for 3 days at room temperature and then poured onto ice (approximately 25 mL). The phases are separated and the organic phase is washed with water (25 mL). The organic phase is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue is purified by column chromatography (silica gel, 10-20% ethyl acetate/hexane) to provide the title compound (1.26 g, 36 %) as a pale yellow oil; 1H NMR (CDCl3) δ 7.5 (m, 6 H), 7.3 (m, 9 H), 6.85 (dd, 1 H), 6.05 (d, 1 H), 4.8 (m, 1 H), 2.1 (m, 2 H); 13C NMR (CDCl3) δ 206.6, 162.9, 144.3, 135.2, 128.8, 128.4, 127.7, 88.2, 73.1, 43.4; IR (KBr) νmax 3061, 1719, 1491, 1449, 1352, 1181, 1107, 1053 cm-1.

1. additionpoured onto ice (approximately 25 mL)
2. customThe phases are separated
3. washthe organic phase is washed with water (25 mL)
4. dry with materialThe organic phase is dried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated under vacuum
7. customThe residue is purified by column chromatography (silica gel, 10-20% ethyl acetate/hexane)