تفاعل #1174785

معادلة التفاعل

butyl lithium

hexane

Boc-leucinal

dry ice acetone

→

3-t-butyloxycarbonylamino-5-methylhex-1-ene

المذيبات

water

tetrahydrofuran

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   أخرىthe -78° C. bath
2. 2
   أخرىwas replaced with a 0° C.
3. 3
   أخرىfor one half hour
4. 4
   workup.ADDITIONwas added
5. 5
   استخلاصExtraction with hexane (4×100 ml)
6. 6
   أخرىprovided a combined organic phase which
7. 7
   غسيلwas washed with brine (100 ml)
8. 8
   تجفيفdried (Na2SO4
9. 9
   تركيزconcentrated

الإجراء التجريبي

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 1.55M 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-butyloxycarbonyl-amino-5 methylhex-1-ene (3.71 g, 60%). Mass spectrum: EI, M+ -57=156; CI, (M+H)+ =214.

المصدر