반응 #89019

반응 방정식

iodomethane

(5S)-5-[(1S)-1-[tert-butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-one

Compound 28e-S

(5S)-5-[(1S)-1-[tert-butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-one

lithium diisopropylamide

→

(3R,5S)-5-[(1S)-1-[tert-butyl(diphenyl)silyl]oxypropyl]-3-methyl-tetrahydrofuran-2-one

수율 87.3%

용매

THF

반응 조건

후처리

1. 1
   workup.ADDITIONAfter addition
2. 2
   workup.STIRRINGthe mixture was stirred at −78° C. for another 1 hour
3. 3
   기타The mixture was quenched with saturated NH4Cl solution (40 mL)
4. 4
   추출extracted with EtOAc (100 mL) twice
5. 5
   세척washed with brine (50 mL)
6. 6
   건조dried over Na2SO4
7. 7
   농축concentrated in vacuo
8. 8
   기타The residue was purified by column chromatography on silica gel (eluting with 1:20 to 1:10 EtOAc in petroleum ether)

실험 절차

To a solution of (5S)-5-[(1S)-1-[tert-butyl(diphenyl)silyl]oxypropyl]tetrahydrofuran-2-one (Compound 28e-S, 3.0 g, 7.8 mmol) in THF (60 mL) at −78° C. was added lithium diisopropylamide (2M in THF, 5.9 mL, 11.8 mmol) dropwise. After addition, the reaction was stirred at −78° C. for 1 hour. To the mixture was added iodomethane (5.5 g, 39 mmol) and the mixture was stirred at −78° C. for another 1 hour. The mixture was quenched with saturated NH4Cl solution (40 mL), extracted with EtOAc (100 mL) twice. The organic layers were combined, washed with brine (50 mL), dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 1:20 to 1:10 EtOAc in petroleum ether) to afford 2.7 g of (3R,5S)-5-[(1S)-1-[tert-butyl(diphenyl)silyl]oxypropyl]-3-methyl-tetrahydrofuran-2-one (compound 28f) as a colourless oil. (Refer to Tetrahedron. 1997, 53, 6281-6294).

출처