反应详情

To a solution of 1-[(E)-3-bromo-1-methyl-1-propenyl]-3-nitrobenzene (Preparation 4, 4 g, 15.6 mmol) in dichloromethane (5 ml) was added rhodium (II) acetate dirner (100 mg, 0.22 nmnol). To the mixture was added dropwise at room temperature over 4.5 h a solution of ethyl diazoacetate (3.1 ml, 2.84 g, 25 mmol) in dichloromethane (15 ml). The mixture was filtered, concentrated in vacuo, and the residue purified by silica column (100 g) chromatography, eluting with 2:1 hexane/dichloromethane then dichloromethane. Product-containing fractions were combined and concentrated in vacuo, then purified further by preparative HPLC (Condition 1). Combination and evaporation of appropriate fractions gave the title compound as a colourless oil (0.5 g, 11%).

1. filtrationThe mixture was filtered
2. concentrationconcentrated in vacuo
3. customthe residue purified by silica column (100 g) chromatography
4. washeluting with 2:1 hexane/dichloromethane
5. concentrationconcentrated in vacuo
6. custompurified further by preparative HPLC (Condition 1)
7. customCombination and evaporation of appropriate fractions