Реакция #89717

Уравнение реакции

Lithium hexamethyldisilazide

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

toluene

→

product

Выход 69.9%

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

Выход 69.9%

Растворители

tetrahydrofuran

tetrahydrofuran

Условия реакции

Обработка

1. 1
   Температураto warm up to −20 Celsius
2. 2
   workup.STIRRINGstirred at −20 Celsius for 3 h
3. 3
   ДругоеAfter quenched with aq ammonium chloride
4. 4
   Экстракцияthe mixture was extracted with ethyl acetate
5. 5
   ПромывкаThe combined organic layers were washed with brine
6. 6
   Другоеdried
7. 7
   Концентрированиеconcentrated
8. 8
   Другоеto dry
9. 9
   Промывкаeluting with 0 to 20% EtOAc in hexane

Методика

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%).

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