반응 #1742948

반응 방정식

ammonium chloride

(S)-(-)-2-phenyl-3-methylbromobutane

magnesium

N-t-butoxycarbonyl-L-leucinal

→

t-butyl [(1S,2S,4S)-2-hydroxy-1-isobutyl-5 -methyl-4-phenylhexyl]carbamate

수율 42.6%

용매

tetrahydrofuran

1,2-dibromoethane

ether

tetrahydrofuran

반응 조건

후처리

1. 1
   기타rose to 50°
2. 2
   온도cooled to -50°
3. 3
   workup.WAITAfter 16 hours at room temperature
4. 4
   건조The organic phase was dried over magnesium sulfate
5. 5
   기타the solvent was evaporated under reduced pressure
6. 6
   기타The residue (24.3 g) was chromatographed on silica gel with a 4:1 mixture of hexane and ether

실험 절차

A solution of 40.9 g (0.18 mol) of (S)-(-)-2-phenyl-3-methylbromobutane in 110 ml of tetrahydrofuran and 0.5 ml of 1,2-dibromoethane was slowly added dropwise to a suspension of 6.6 g of magnesium in 25 ml of ether. The temperature rose to 50°. Thereafter, the reaction mixture was stirred at 50° for a further 2 hours and then cooled to -50°. Then, a solution of 13 g (0.06 mol) of N-t-butoxycarbonyl-L-leucinal in 40 ml of tetrahydrofuran was added slowly. After 16 hours at room temperature, the reaction mixture was treated with 200 ml of a 20% ammonium chloride solution. The organic phase was dried over magnesium sulfate and the solvent was evaporated under reduced pressure. The residue (24.3 g) was chromatographed on silica gel with a 4:1 mixture of hexane and ether, to obtain 9.3 g of t-butyl [(1S,2S,4S)-2-hydroxy-1-isobutyl-5 -methyl-4-phenylhexyl]carbamate which has a melting point of 95°-96° after crystallization from hexane.

출처