反応 #216440

反応方程式

diisopropylamine

n-butyllithium

hexane

ketone

2-Acetyl-3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalene

ethyl (E)-3-formyl-2-butenoate

ethyl (E)-3-formyl-2-butenoate

NH4Cl

→

alcohol

収率 80.0%

Ethyl (E)-4-hydroxy-3-methyl-6-oxo-6-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthalenyl)-2-hexenoate

収率 80.0%

溶媒

THF

THF

THF

反応条件

後処理

1. 1
   workup.STIRRINGThe mixture was stirred for 20 min
2. 2
   workup.ADDITIONwas added slowly
3. 3
   workup.STIRRINGThe mixture was stirred for 35 min at -78° C.
4. 4
   抽出extracted with 40% ethyl acetate/hexane
5. 5
   乾燥The combined organic layers were dried over anhydrous MgSO4
6. 6
   ろ過filtered
7. 7
   濃縮concentrated
8. 8
   その他to afford a light-yellow solid

実験手順

To a solution of diisopropylamine (0.5 mL, 3.52 mmol) in 7 mL of THF at -78° C. under argon was added a 1.6M solution of n-butyllithium in hexane (2.2 mL, 3.52 mmol). The mixture was stirred for 25 min, and a solution of ketone 39 (0.78 g, 3.2 mmol) in 4 mL of THF was added slowly. The mixture was stirred for 20 min, and a solution of ethyl (E)-3-formyl-2-butenoate 40 (0.45 g, 3.2 mmol) (ethyl (E)-3-formyl-2-butenoate 40 is readily available from Fluka) in 3 mL of THF was added slowly. The mixture was stirred for 35 min at -78° C., poured into saturated aqueous NH4Cl, and extracted with 40% ethyl acetate/hexane. The combined organic layers were dried over anhydrous MgSO4, filtered, and concentrated to afford a light-yellow solid. Flash chromatography yielded the desired alcohol 41 as a white crystalline solid (0.98 g, 80%): m.p. 126°-128° C.; Rf 0.13 (10% ethyl acetate/hexane). The structure of the product was also confirmed using IR, 1H NMR and mass spectroscopy.

出典