反应详情

温度

-78 °C

To a stirred suspension of methyltriphenyl phosphonium bromide (10.97 g, 30.70 mmol) in anhydrous tetrahydrofuran (200 ml) at -78° C. (dry ice/acetone bath) under an argon atmosphere, was added n-butyl lithium (19.8 ml of a 1.55 M hexane solution) dropwise over the course of 5 minutes. After 10 minutes, the -78° C. bath was replaced with a 0° C. bath for one half hour, at which time the resulting orange solution was cooled again to -78° C. The solution was then added dropwise by cannula to a stirred -78° C. solution of Boc-cyclohexylalaninal (27.91 mmol) in anhydrous tetrahydrofuran (30 ml) over the course of one half hour. The mixture was then allowed to warm to room temperature during a 3 hour period after which water (150 ml) was added. Extraction with hexane (4×100 ml) provided a combined organic phase which was washed with brine (100 ml), dried (Na2SO4), and concentrated to give crude product. Chromatography with ether/hexane (1/9) provided the pure desired compound. Mass spectrum: (M+H)+ =254.

1. customthe -78° C. bath
2. customwas replaced with a 0° C.
3. customfor one half hour
4. additionwas added
5. extractionExtraction with hexane (4×100 ml)
6. customprovided a combined organic phase which
7. washwas washed with brine (100 ml)
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated
10. customto give crude product