Diethyl Ether → Tert-butyl 2-hydroxy-2-methylcyclopentylcarbamate

HRID 1408939ノート

反応式

HRID 1408939 の反応式
[CH3:1]COCC.C[Li].[O:8]=[C:9]1[CH2:13][CH2:12][CH2:11][CH:10]1[NH:14][C:15](=[O:21])[O:16][C:17]([CH3:20])([CH3:19])[CH3:18].[Cl-].[Ce+3].[Cl-].[Cl-]>O1CCCC1>[OH:8][C:9]1([CH3:1])[CH2:13][CH2:12][CH2:11][CH:10]1[NH:14][C:15](=[O:21])[O:16][C:17]([CH3:18])([CH3:20])[CH3:19]

参加物

6

反応物 4

HCID 3283Diethyl EtherHCID 24636Cerium(III) chlorideHCID 357962tert-butyl N-(2-oxocyclopentyl)carbamateHCID 178418348HCID 178418348、化合物

生成物 1

HCID 59281702Tert-butyl 2-hydroxy-2-methylcyclopentylcarbamate収率 82%

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒

実験手順

A 1.6 M ether solution of methyllithium (13.59 mL, 21.75 mmol) was added to a stirred suspension of tert-butyl 2-oxocyclopentylcarbamate (1.97 g, 9.89 mmol, from Step 2) and cerium(III) chloride (5.36 g, 21.75 mmol) in tetrahydrofuran (50 mL) at −78° C. under nitrogen. After 2.5 h at −78° C., the mixture was quenched with saturated ammonium chloride, allowed to warm to room temperature, and filtered through a short bed of Celite to remove insoluble cerium salt. The filter cake was rinsed with ethyl acetate. The filtrated was extracted with ethyl acetate three times. The combined ethyl acetate phase was washed with saturated ammonium chloride and brine respectively, dried (MgSO4), filtered and concentrated. Silica gel chromatography, eluting with 0 to 50% ethyl acetate in hexanes, gave tert-butyl 2-hydroxy-2-methylcyclopentylcarbamate as yellow solid (1.47 g, 82% yield). 1H NMR analysis indicated the presence of approximately a 3:1 diastereomeric mixture.

後処理

  1. customthe mixture was quenched with saturated ammonium chloride
  2. filtrationfiltered through a short bed of Celite
  3. customto remove insoluble cerium salt
  4. washThe filter cake was rinsed with ethyl acetate
  5. extractionThe filtrated was extracted with ethyl acetate three times
  6. washThe combined ethyl acetate phase was washed with saturated ammonium chloride and brine respectively
  7. dry with materialdried (MgSO4)
  8. filtrationfiltered
  9. concentrationconcentrated
  10. washSilica gel chromatography, eluting with 0 to 50% ethyl acetate in hexanes

出典と根拠

ORDレコード
ord-8036fafc7a4e4e8e842ad322318190fa
出典データセット
uspto-grants-2014_12
特許番号
US08921368B2

反応ノート

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