Chloroform → 3-Acetoxy-5-t-butyldimethylsiloxycyclopent-1-ene

HRID 2393891

반응식

HRID 2393891 반응식
[Si:1]([O:8][C@@H:9]1[CH2:13][C@H:12]([OH:14])[CH:11]=[CH:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].C(N(CC)CC)C.[C:22](OC=C)(=[O:24])[CH3:23].C(Cl)(Cl)Cl>COC(C)(C)C>[Si:1]([O:8][CH:9]1[CH2:13][CH:12]([O:14][C:22](=[O:24])[CH3:23])[CH:11]=[CH:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

참가 물질

6

반응물 4

HCID 6212Chloroform2회HCID 7904Vinyl AcetateHCID 8471TriethylamineHCID 101767472-Cyclopenten-1-ol, 4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-, cis-2회

생성물 1

HCID 127633543-Acetoxy-5-t-butyldimethylsiloxycyclopent-1-ene수율 51.1%

시약·촉매·용매 1

HCID 15413tert-Butyl methyl ether용매

실험 절차

Cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (10.0 g, 46.6 mmol, prepared in example 3a) is dissolved in tert-butyl methyl ether (60 mL, anhydrous). To the solution is added triethylamine (4.5 mL, 32.3 mmol), pancreatin (30 g, available from Sigma Chemical Company), and vinyl acetate (22 mL, 239 mmol). The reaction is allowed to stir for 7 hours at room temperature. The reaction is then filtered through diatomaceous earth and the filtrate is concentrated under vacuum. The products are separated by chromatography on silica gel (5% to 20% ethyl acetate/hexane) to provide (-)-acetic acid 4-tert-butyldimethylsilyloxy-cyclopent-2-enyl ester (B. 6.1 g, 51% yield, 99% ee), [α]D -0.2°, (c=0.52, chloroform) as a yellow oil and (-)-cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol (A, 4.7 g, 47% yield, >99% ee), [α]D -18.6°, (c=1.01, chloroform) as a yellow oil.

후처리

  1. filtrationThe reaction is then filtered through diatomaceous earth
  2. concentrationthe filtrate is concentrated under vacuum
  3. customThe products are separated by chromatography on silica gel (5% to 20% ethyl acetate/hexane)

출처 및 근거

ORD 기록
ord-11e5f7dce80c4e9eaa4c55eb47b61dc5
출처 데이터셋
uspto-grants-1998_09
특허 번호
US05808112

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