Reaktion #9002

Reaktionsgleichung

sodium potassium tartrate

ester

2-(tert-butoxycarbonylamino-methyl)-oxazole-4-carboxylic acid methyl ester

DIBAL-H

→

(4-hydroxymethyl-oxazol-2-ylmethyl)-carbamic acid tert-butyl ester

Ausbeute 28.4%

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture was stirred rapidly for 30 minutes (until the aqueous and organic layers
2. 2
   Sonstigewere then separated
3. 3
   ExtraktionThe aqueous layer was extracted twice with dichloromethane
4. 4
   TrocknenThe combined organic fractions were then dried over anhydrous sodium sulfate
5. 5
   Einengenconcentrated
6. 6
   SonstigePurification by chromatography on silica gel (5% methanol in dichloromethane)

Vorschrift

The ester (178 mg, 0.695 mmol) in 0° C. dichloromethane (8 mL) was treated with DIBAL-H (1 M in dichloromethane, 2.08 mL, 2.08 mmol). The mixture was then stirred at 0° C. for 2 hours before being treated with aqueous 5% sodium potassium tartrate (8 mL). The mixture was stirred rapidly for 30 minutes (until the aqueous and organic layers clarified), and the layers were then separated. The aqueous layer was extracted twice with dichloromethane. The combined organic fractions were then dried over anhydrous sodium sulfate and concentrated. Purification by chromatography on silica gel (5% methanol in dichloromethane) gave (4-hydroxymethyl-oxazol-2-ylmethyl)-carbamic acid tert-butyl ester as an oil (45 mg, 28%). 1H NMR (CDCl3) δ 1.40 (s, 9H), 4.43 (d, 2H, J=5.6 Hz), 4.56 (s, 2H), 5.37 (s, 1H), 7.54 (s, 1H).

Quelle