Реакция #357779

Уравнение реакции

iodoethane

lithium hexamethyldisilazide

methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]cyclopent-2-ene-1-carboxylate

→

desired product

Methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]-1-ethylcyclopent-2-ene-1-carboxylate

Растворители

tetrahydrofuran

tetrahydrofuran

Условия реакции

Обработка

1. 1
   workup.ADDITIONwas added in one portion
2. 2
   ДругоеThe reaction was quenched with aqueous NH4Cl
3. 3
   ДругоеThe organic layer was separated
4. 4
   Экстракцияthe aqueous layer was further extracted with ether three times
5. 5
   ПромывкаThe combined organic layers were then washed with brine
6. 6
   Сушкаdried over Na2SO4
7. 7
   Фильтрацияfiltered
8. 8
   Концентрированиеconcentrated
9. 9
   Другоеpurified by flash column chromatography

Методика

To a 1.00 M soluition of lithium hexamethyldisilazide in tetrahydrofuran (61.5 mL, 61.5 mmol) was added a solution of methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]cyclopent-2-ene-1-carboxylate (6.71 g, 27.8 mmol) in tetrahydrofuran (10.0 mL) at −78° C. over 10 min. The resulted light brown solution was stirred at −78° C. for 30 min before iodoethane (2.67 mL, 33.4 mmol) was added in one portion. The mixture was then kept at −25° C. overnight. The reaction was quenched with aqueous NH4Cl. The organic layer was separated and the aqueous layer was further extracted with ether three times. The combined organic layers were then washed with brine, dried over Na2SO4, filtered, concentrated and purified by flash column chromatography to yield the desired product as a 7:1 cis/trans mixture (4.83 g, 65%). MS calculated for C14H23NO4: (M+H) 170.2; found 170.1 (M+H-Boc).

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