반응 #87231

반응 방정식

sodium bicarbonate

(3R,4R,5S)-4-hydroxy-5-methyl-3-phenethyldihydrofuran-2(3H)-one

2,6-dimethylpyridine

triisopropylsilyl trifluoromethanesulfonate

→

(3R,4R,5S)-5-methyl-3-phenethyl-4-((triisopropylsilyl)oxy)dihydro-furan-2(3H)-one

수율 59.2%

용매

CH2Cl2

반응 조건

후처리

1. 1
   workup.ADDITIONmixed thoroughly
2. 2
   기타The phases were separated
3. 3
   추출the aqueous extracted with CH2Cl2 (2×25 mL)
4. 4
   건조The combined CH2Cl2 extracts were dried
5. 5
   농축concentrated to a colorless oil which
6. 6
   기타was purified by flash chromatography (SiO2, 0→50% EtOAc/hexanes)

실험 절차

To a solution of (3R,4R,5S)-4-hydroxy-5-methyl-3-phenethyldihydrofuran-2(3H)-one (800 mg, 3.63 mmol) in CH2Cl2 (20 mL) were added 2,6-dimethylpyridine (592 μl, 5.08 mmol) and triisopropylsilyl trifluoromethanesulfonate (1171 μL, 4.36 mmol) at 0° C., and the mixture was warmed to room temperature while stirring overnight. The reaction mixture was poured onto 50 mL saturated sodium bicarbonate solution and mixed thoroughly. The phases were separated, and the aqueous extracted with CH2Cl2 (2×25 mL). The combined CH2Cl2 extracts were dried and concentrated to a colorless oil which was purified by flash chromatography (SiO2, 0→50% EtOAc/hexanes) to give (3R,4R,5S)-5-methyl-3-phenethyl-4-((triisopropylsilyl)oxy)dihydro-furan-2(3H)-one (809 mg, 53%): 1H NMR (400 MHz, CDCl3) δ 7.33-7.25 (m, 2H), 7.25-7.17 (m, 3H), 3.98 (dd, J=5.9, 4.8 Hz, 1H), 4.34-4.24 (m, 1H), 2.99-2.88 (m, 1H), 2.88-2.76 (m, 1H), 2.61-2.51 (m, 1H), 2.04-1.94 (m, 2H), 1.43 (d, J=6.5 Hz, 3H), 1.09-0.99 (m, 21H); 13C NMR (101 MHz, CDCl3) δ 176.64, 140.98, 128.57, 128.51, 126.16, 82.10, 79.45, 49.17, 32.96, 31.14, 19.10, 18.00, 17.71; ESIMS m/z 378 ([M+H]+).

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