Réaction #159799

Équation de réaction

water

4-benzyl-6-[2-bromo-5-((2S,3S,4R,5R,6R)-3,4,5-tris-benzyloxy-6-benzyloxymethyl-tetrahydro-pyran-2-yl)-benzyl]-3,4-dihydro-2H-benzo[1,4]oxazine

cyclopropylboronic acid

potassium phosphate

→

4-benzyl-6-[2-cyclopropyl-5-((2S,3S,4R,5R,6R)-3,4,5-tris-benzyloxy-6-benzyloxymethyl-tetrahydro-pyran-2-yl)-benzyl]-3,4-dihydro-2H-benzo[1,4]oxazine

Rendement 95.0%

Solvants

toluene water

Conditions de réaction

Traitement

1. 1
   AutreThe reaction mixture was degassed for 45 min
2. 2
   Températurethe reaction mixture was cooled to room temperature
3. 3
   ExtractionThe resulting mixture was extracted with ethyl acetate (2×25 mL)
4. 4
   Lavagewashed with water and brine
5. 5
   Séchagedried over sodium sulfate
6. 6
   Concentrationconcentrated
7. 7
   Autrepurified by column chromatography

Mode opératoire

To a stirred solution of 4-benzyl-6-[2-bromo-5-((2S,3S,4R,5R,6R)-3,4,5-tris-benzyloxy-6-benzyloxymethyl-tetrahydro-pyran-2-yl)-benzyl]-3,4-dihydro-2H-benzo[1,4]oxazine (0.35 g, 0.38 mmol) in toluene:water (10:1 mixture, 10 mL) was added cyclopropylboronic acid (49.2 mg, 0.5731 mmol) tricyclohexylphosphine (26.7 mg, 0.0955 mmol), and potassium phosphate (0.28 g, 1.34 mmol). The reaction mixture was degassed for 45 min then palladium (II) acetate (8.5 mg, 0.03821 mmol) was added. After heating overnight at 100° C., the reaction mixture was cooled to room temperature and water (20 mL) was added. The resulting mixture was extracted with ethyl acetate (2×25 mL), washed with water and brine, then dried over sodium sulfate, concentrated and purified by column chromatography to furnish 4-benzyl-6-[2-cyclopropyl-5-((2S,3S,4R,5R,6R)-3,4,5-tris-benzyloxy-6-benzyloxymethyl-tetrahydro-pyran-2-yl)-benzyl]-3,4-dihydro-2H-benzo[1,4]oxazine (317 mg). The product was taken up for the next step without characterization.

Source