Methanol → tert-Butyl hydrogen (1,5-dihydroxypentan-2-yl)carbonimidate

HRID 246130Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 246130
[BH4-].[Li+].C([O:5][C:6](=O)[C@@H:7]([NH:15][C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17])[CH2:8][CH2:9][C:10](OCC)=[O:11])C.CO.O>C1COCC1.C(OCC)(=O)C>[C:19]([O:18][C:16](=[O:17])[NH:15][C@H:7]([CH2:6][OH:5])[CH2:8][CH2:9][CH2:10][OH:11])([CH3:22])([CH3:20])[CH3:21]

Komponenten

7

Edukt 4

HCID 887MethanolHCID 962WaterHCID 4148881Lithium borohydrideHCID 14420344(S)-Diethyl 2-(tert-butoxycarbonylamino)pentanedioate

Produkt 1

HCID 2734851tert-Butyl hydrogen (1,5-dihydroxypentan-2-yl)carbonimidateAusbeute 83 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 8028TetrahydrofuranLösungsmittelHCID 8857Ethyl AcetateLösungsmittel

Versuchsvorschrift

Lithium borohydride (2.0 M in THF, 4.12 ml, 8.24 mmol) was cooled in an ice bath and a solution of (S)-2-tert-butoxycarbonylamino-pentanedioic acid diethyl ester (0.5 g, 1.65 mmol) in THF (5.5 ml) was added dropwise. The reaction was warmed to room temperature and stirred 16 h. Methanol was added very slowly to the reaction mixture. After a delayed, vigorous gas evolution had subsided, water and ethyl acetate were added. The aqueous layer was extracted with ethyl acetate five times, and the combined organic layers were washed with sodium chloride solution and dried over sodium sulfate. After evaporation, the residue was purified by silica gel chromatography (methanol/dichloromethane) to give 0.3 g (83%) of ((S)-4-hydroxy-1-hydroxymethyl-butyl)-carbamic acid tert-butyl ester. (M+Na)+=242.

Aufarbeitung

  1. extractionThe aqueous layer was extracted with ethyl acetate five times
  2. washthe combined organic layers were washed with sodium chloride solution
  3. dry with materialdried over sodium sulfate
  4. customAfter evaporation
  5. customthe residue was purified by silica gel chromatography (methanol/dichloromethane)

Quellen und Nachweise

ORD-Eintrag
ord-3126df2b95d14a2fa972e9a1c14753c6
Quelldatensatz
uspto-grants-2014_02
Patentnummer
US08658646B2

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