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

HRID 2549

反応式

HRID 2549 の反応式
[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]

参加物

6

反応物 4

HCID 6212Chloroform2 回HCID 7904Vinyl AcetateHCID 8471TriethylamineHCID 101767472-Cyclopenten-1-ol, 4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-, cis-2 回

生成物 1

HCID 127633543-Acetoxy-5-t-butyldimethylsiloxycyclopent-1-ene収率 51.1%

試薬・触媒・溶媒 1

HCID 15413tert-Butyl methyl ether溶媒

実験手順

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.

後処理

  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)

出典と根拠

ORDレコード
ord-4080122b276c4fa69f2e3e82eeb5a920
出典データセット
uspto-grants-1998_03
特許番号
US05728899

関連ノート

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