Réaction #9002

Équation de réaction

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

Rendement 28.4%

Solvants

dichloromethane

Conditions de réaction

Traitement

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

Mode opératoire

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).

Source