反应详情

To a solution of isopropylamine (1.87 ml) in dry tetrahydrofuran (50 ml) was added dropwise 1.15M n-butyllithium in hexane solution (10.6 ml) at -78° C. The mixture was stirred for 20 min at -78° C. to give lithium diisopropylamide. To the obtained lithium diisopropylamide solution was added a solution of dimethyl carboxymethylphosphonate (1.02 g) in dry tetrahydrofuran (3 ml) at -78° C. After stirred for 10 min, to the mixture was added the aldehyde compound (prepared in reference example 1, 1.38 g) at room temperature. The mixture was stirred for 1 h at room temperature. After acidified by adding 1N hydrochloric acid until pH 3, the mixture was extracted with ethyl acetate. The extract was washed with water and a saturated aqueous solution of sodium chloride, successively, dried over anhydrous magnesium sulfate, and evaporated. The residue was crystallized from ethyl acetate-hexane (3:7) to give the title compound (1.07 g) as white powder having the following physical data.

1. stirringThe mixture was stirred for 1 h at room temperature
2. extractionthe mixture was extracted with ethyl acetate
3. washThe extract was washed with water
4. dry with materiala saturated aqueous solution of sodium chloride, successively, dried over anhydrous magnesium sulfate
5. customevaporated
6. customThe residue was crystallized from ethyl acetate-hexane (3:7)