反应详情

A Grignard reagent of 3.50 g (0.021 mol) of 5-bromo-2-methyl-2-pentene in 13 ml of ether and 0.62 g (0.026 mol) of magnesium turnings in 14 ml of ether was added slowly at −25° under N2 to a stirred solution of 5.54 g (0.024 mol) of 5-(2-phenyl-1,3-dioxolan-2-yl)-2-pentanone obtained under b) in 20 ml of ether. During the introduction, the temperature was left rising up to −5° C. and the reaction mixture left stirring for 45 min. Then a saturated solution of NH4Cl was added and the formation of a white precipitate was observed. Extraction with ether (2×), washing with water (3×), drying (Na2SO4) and concentrating gave 6.24 g of the crude product. Column chromatography (SiO2, heptane/ether 7:3) gave 2.53 g (38%) of a yellow oil.

1. waitDuring the introduction, the temperature was left
2. customrising up to −5° C.
3. waitthe reaction mixture left
4. extractionExtraction with ether (2×)
5. washwashing with water (3×)
6. dry with materialdrying (Na2SO4)
7. concentrationconcentrating
8. customgave 6.24 g of the crude product