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-leucinal (6.00 g, 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 3-t-butyloxycarbonylamino-5-methylhex-1-ene (6.5 g). Chromatography with ether/hexane (1/9) provided pure 3-t-butyloxycarbonylamino-5-methylhex-1-ene (3.71 g, 60%). Mass spectrum: EI, M+ -57=156; CI, (M+H)30 =214.

1. customdropwise over the course of 5 minutes
2. customthe -78° C. bath
3. customwas replaced with a 0° C.
4. customfor one-half hour
5. additionwas added
6. extractionExtraction with hexane (4×100 mL)
7. customprovided a combined organic phase which
8. washwas washed with brine (100 mL)
9. dry with materialdried (Na2SO4 )
10. concentrationconcentrated
11. customto give crude 3-t-butyloxycarbonylamino-5-methylhex-1-ene (6.5 g)