Réaction #89717

Équation de réaction

Lithium hexamethyldisilazide

1-benzyl 4-methyl(2S)-2-[benzyl((2S)-2-(1-ethoxyethoxy)-3-[(4-methylphenyl)sulfonyl]oxypropyl)amino]succinate

toluene

→

product

Rendement 69.9%

2-benzyl 3-methyl(2S,3S,5R)-1-benzyl-5-(1-ethoxyethoxy)piperidine-2,3-dicarboxylate

Rendement 69.9%

Solvants

tetrahydrofuran

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   Températureto warm up to −20 Celsius
2. 2
   workup.STIRRINGstirred at −20 Celsius for 3 h
3. 3
   AutreAfter quenched with aq ammonium chloride
4. 4
   Extractionthe mixture was extracted with ethyl acetate
5. 5
   LavageThe combined organic layers were washed with brine
6. 6
   Autredried
7. 7
   Concentrationconcentrated
8. 8
   Autreto dry
9. 9
   Lavageeluting with 0 to 20% EtOAc in hexane

Mode opératoire

To a solution of 1-benzyl 4-methyl(2S)-2-[benzyl((2S)-2-(1-ethoxyethoxy)-3-[(4-methylphenyl)sulfonyl]oxypropyl)amino]succinate (35.7 g, 0.0569 mol) in a mixture of tetrahydrofuran (95.5 mL, 1.18 mol) and toluene (490 mL, 4.6 mol) at −78 Celsius was was added 1.00 M of Lithium hexamethyldisilazide in tetrahydrofuran (68.2 mL). The reaction was stirred at −78 Celsius overnight then allowed to warm up to −20 Celsius and stirred at −20 Celsius for 3 h. After quenched with aq ammonium chloride, the mixture was extracted with ethyl acetate. The combined organic layers were washed with brine, dried and concentrated to dry. The residue was applied on silica gel column, eluting with 0 to 20% EtOAc in hexane, to afford the product (18.1 g, 69.9%). MS (ESI): (M+H)+=456.2. The corresponding diastereoisomer was also obtained (4.52 g, 17.5%).

Source