반응 #89717

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Lithium hexamethyldisilazide

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

toluene

→

product

수율 69.9%

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

수율 69.9%

용매

tetrahydrofuran

tetrahydrofuran

반응 조건

후처리

1. 1
   온도to warm up to −20 Celsius
2. 2
   workup.STIRRINGstirred at −20 Celsius for 3 h
3. 3
   기타After quenched with aq ammonium chloride
4. 4
   추출the mixture was extracted with ethyl acetate
5. 5
   세척The combined organic layers were washed with brine
6. 6
   기타dried
7. 7
   농축concentrated
8. 8
   기타to dry
9. 9
   세척eluting with 0 to 20% EtOAc in hexane

실험 절차

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%).

출처