反応 #65313

反応方程式

allyl magnesium chloride

n-butyl lithium

1,1,1,3,3,3-hexamethyldisilazane

ammonium chloride

p-tolualdehyde

→

lithium bis(trimethylsilyl)amide

溶媒

THF

tetrahydrofuran

water

THF

反応条件

後処理

1. 1
   その他the temperature between -40° and -50° C
2. 2
   その他the temperature between 10° and 15° C
3. 3
   workup.STIRRINGAfter stirring for 30 min the reaction
4. 4
   その他The layers were separated
5. 5
   抽出the aqueous layer was extracted with ether/hexane
6. 6
   洗浄The organic layers were washed with brine
7. 7
   乾燥dried over sodium sulfate
8. 8
   その他evaporated
9. 9
   workup.ADDITIONThe residue was added to a solution of (1R)-(-)-10-camphorsulfonic acid (62.5 gm) in ethyl acetate (1 L)
10. 10
    温度with cooling
11. 11
    workup.WAITOn standing overnight at rt
12. 12
    その他crystals formed which
13. 13
    ろ過were filtered
14. 14
    洗浄washed with ethyl acetate
15. 15
    workup.STIRRINGThe crystals were then stirred with refluxing ethyl acetate (300 mL)
16. 16
    ろ過filtered
17. 17
    洗浄washed with ethyl acetate

実験手順

A solution of lithium bis(trimethylsilyl)amide was prepared by adding 2.5M n-butyl lithium (208 mL) to a solution of 1,1,1,3,3,3-hexamethyldisilazane (110 mL, 0.52 mol) in tetrahydrofuran (THF) (140 mL) at 0° C. After stirring for 15 min, this solution was added via a cannula to a solution of p-tolualdehyde (59 mL, 0.5 mol) in THF (100 mL), while keeping the temperature between -40° and -50° C. The reaction mixture was then allowed to warm to 10° C. over 30 min. A 2M solution of allyl magnesium chloride (260 mL) in THF was added, keeping the temperature between 10° and 15° C. After stirring for 30 min the reaction was poured into a solution of ammonium chloride (150 gm) in water (1 L). The layers were separated and the aqueous layer was extracted with ether/hexane. The organic layers were washed with brine, combined, dried over sodium sulfate and evaporated. The residue was added to a solution of (1R)-(-)-10-camphorsulfonic acid (62.5 gm) in ethyl acetate (1 L) with cooling. On standing overnight at rt, crystals formed which were filtered and washed with ethyl acetate. The crystals were then stirred with refluxing ethyl acetate (300 mL), filtered and washed with ethyl acetate. The pure title compound weighed 60.7 gm. [α]D =-27.16 (c=0.5, 100% EtOH).

出典