Chloroform → (+)-Acetic acid cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enyl ester

HRID 2550

反応式

HRID 2550 の反応式
[O:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH:2]1[O:7][C@@H:8]1[CH2:12][C@H:11]([OH:13])[CH:10]=[CH:9]1.C(N(CC)CC)C.[C:21](OC=C)(=[O:23])[CH3:22].C(Cl)(Cl)Cl>COC(C)(C)C>[O:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH:2]1[O:7][C@@H:8]1[CH2:12][C@H:11]([O:13][C:21](=[O:23])[CH3:22])[CH:10]=[CH:9]1

参加物

6

反応物 4

HCID 6212Chloroform2 回HCID 7904Vinyl AcetateHCID 8471TriethylamineHCID 13623252cis-4-Tetrahydropyranyloxy 2-cyclopentenol2 回

生成物 1

HCID 13623284(+)-Acetic acid cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enyl ester収率 45%

試薬・触媒・溶媒 1

HCID 15413tert-Butyl methyl ether溶媒

実験手順

Cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enol (1.091 g, 5.92 mmol, prepared in example 6) is dissolved in tert-butyl methyl ether (8.6 mL, anhydrous). To the solution is added triethylamine (0.59 mL, 4.2 mmol), pancreatin (3.2 g, available from Sigma Chemical Company), and vinyl acetate (2.7 mL, 29 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 (10% to 20% ethyl acetate/hexane) to provide (-)-acetic acid cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enyl ester (B, 601 mg, 45% yield, 91% ee) [α]D =-19.8°,(c=1.00, chloroform) as a yellow oil and (-)-cis-4-(tetrahydro-pyran-2-yloxy)-cyclopent-2-enol (A, 560 mg, 50% yield, 94% ee), [α]D =-9.9°, (c=1.06, 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 (10% to 20% ethyl acetate/hexane)

出典と根拠

ORDレコード
ord-23a5242235f843fa9d331c47debf3305
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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