Réaction #2010

Équation de réaction

allyl ester

N-(t-Butoxycarbonyl)-D-homophenylalanine allyl ester

sodium bicarbonate

anisole

trifluoroacetic acid

→

D-Homophenylalanine allyl ester

Solvants

methylene chloride

methylene chloride

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGThe reaction mixture was stirred at room temperature for a further 2 h
2. 2
   Autrethe volatiles removed on a rotary evaporator under reduced pressure
3. 3
   Autreto give a thick oil
4. 4
   Séchagethe methylene chloride layer dried over anhydrous magnesium sulfate powder
5. 5
   Filtrationfiltered
6. 6
   Autrethe volatiles removed under reduced pressure
7. 7
   Autreafter evaporation
8. 8
   Autrewas chromatographed on silica gel using a solvent gradient
9. 9
   AutreThe product (1.1 g; 81.7%) was isolated after the chromatography

Mode opératoire

The allyl ester from Step A of this Example (1.96 g; 6.136 mmol) was dissolved in dry methylene chloride (10 ml) and anisole (5 ml) was added. The mixture was stirred at room temperature and trifluoroacetic acid was added drop by drop to the ester over 5 minutes. The reaction mixture was stirred at room temperature for a further 2 h then the volatiles removed on a rotary evaporator under reduced pressure to give a thick oil. The oil was dissolved in methylene chloride (50 ml) and shaken with a saturated aqueous solution of sodium bicarbonate. The aqueous layer was discarded and the methylene chloride layer dried over anhydrous magnesium sulfate powder, filtered and the volatiles removed under reduced pressure. The oil that remained after evaporation was chromatographed on silica gel using a solvent gradient beginning with ethyl acetate and hexanes (1:1) to neat ethyl acetate and then with a eluant of ethanol and ethyl acetate in the ratio 1:4 v/v. The product (1.1 g; 81.7%) was isolated after the chromatography. FAB-MS:- calculated for C13H17NO2 219.1; found 219.8 (M).

Source