Reaktion #417307

Reaktionsgleichung

3-amino-2-hydroxy-2,4-dimethylpentane

beta-benzyl-N-benzyloxycarbonyl-L-aspartyl-D-alanine

N-methylmorpholine

ethyl chloroformate

→

2-Hydroxy-2,4-dimethy-3-pentanone

Lösungsmittel

tetrahydrofuran

ethyl acetate hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added 0.55 ml
2. 2
   workup.STIRRINGstirred overnight
3. 3
   Sonstigeto obtain

Vorschrift

To a solution of 2.14 g. (5.0 mmole) beta-benzyl-N-benzyloxycarbonyl-L-aspartyl-D-alanine in 35 ml. tetrahydrofuran cooled to -15° was added 0.55 ml. (5.0 mmole) N-methylmorpholine and 0.48 ml. (5.0 mmole) ethyl chloroformate. The mixture was stirred at -15° to -10° C. for two minutes and 0.66 g. (5.0 mmole) 3-amino-2-hydroxy-2,4-dimethylpentane was added. The mixture was allowed to warm to room temperature, stirred overnight and worked-up as described in Example 5, Part B, to obtain the diprotected dipeptide amide, Rf 0.27 (TLC, ethyl acetate/hexane, 1:1, phosphomolybdic acid spray, heat) which was used directly in the next step.

Quelle