反应详情

Diethyl azodicarboxylate (0.235 ml, 1.49 mmol) was added at 0° C. to a stirred solution of triphenylphosphine (0.392 g, 1.49 mmol) and 2-(9H-fluoren-9-yl)-ethanol (0.208 g, 1.0 mmol) in dry THF (5 ml) and the mixture stirred for 5 min. A solution of ethyl 2-ethoxy-3-(4-hydroxy-phenyl)-propionate (0.356 g, 1.49 mmol) in dry THF (5 ml) was then added, the mixture allowed to warm to room temperature and stirring continued for 20 h. The resulting mixture was treated with water (50 ml), and the products extracted into dichloromethane (4×50 ml). The extracts were combined, washed with brine, dried (Na2SO4) and evaporated to a colourless gum. This was then purified by column chromatography on SiO2 (15% Et2O in petroleum eluent) to give the title compound as a colourless gum; 0.20 g (47%).

1. stirringstirring
2. waitcontinued for 20 h
3. extractionthe products extracted into dichloromethane (4×50 ml)
4. washwashed with brine
5. dry with materialdried (Na2SO4)
6. customevaporated to a colourless gum
7. customThis was then purified by column chromatography on SiO2 (15% Et2O in petroleum eluent)