Reaktion #521928

Reaktionsgleichung

3-amino-2,2,4,4-tetramethyltetrahydrothiophene

N-t-butoxycarbonyl-D-serine

triethylamine

ethyl chloroformate

→

N(2,2,4,4-tetramethyltetrahydrothiophene-3-yl)-t-butoxycarbonyl-D-serine amide

Lösungsmittel

tetrahydrofuran

Ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAt this temperature is added 0.96 ml
2. 2
   Temperaturto warm to room temperature
3. 3
   Waschenthe mixture is washed twice with 50 ml
4. 4
   TrocknenThe organic layer is dried (Na2SO4)
5. 5
   Sonstigeevaporated to dryness at reduced pressure

Vorschrift

To a solution of 2.26 g. (11 mmole) of N-t-butoxycarbonyl-D-serine in 75 ml. of tetrahydrofuran is added 1.47 ml. (10 mmole) of triethylamine and the mixture cooled to -10° C. At this temperature is added 0.96 ml. (10 mmole) of ethyl chloroformate and stirring continued for 15 minutes. After cooling to -20° C., 1.6 g. (10 mmole) of dl-3-amino-2,2,4,4-tetramethyltetrahydrothiophene is added and the resulting mixture is allowed to warm to room temperature. Ethyl acetate is added and the mixture is washed twice with 50 ml. portions of 5% (by weight) aqueous citric acid, aqueous sodium bicarbonate (1 ×50 ml.) and saturated brine (1 ×50 ml.). The organic layer is dried (Na2SO4) and evaporated to dryness at reduced pressure to afford N(2,2,4,4-tetramethyltetrahydrothiophene-3-yl)-t-butoxycarbonyl-D-serine amide. This product is used without further purification in the next step. ##STR113##

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