Reaction #9002

Reaction equation

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

Yield 28.4%

Solvents

dichloromethane

Conditions

Workup

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

Procedure

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