Reaktion #7955

Reaktionsgleichung

iodomethane

9a-butyl-7-methoxymethoxy-4-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

LDA

NH4Cl

dry ice acetone

→

(2SR,9aSR)-9a-butyl-2,4-dimethyl-7-methoxymethoxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one

Lösungsmittel

EtOAc

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added by syringe
2. 2
   Temperaturto slowly warm to room temperature
3. 3
   workup.STIRRINGstirred at room temperature overnight
4. 4
   ExtraktionThe aqueous phase was extracted with more EtOAc (20 mL)
5. 5
   WaschenThe combined organics were washed with 5% NaHCO3, water, and brine
6. 6
   Trocknendried over MgSO4
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under vacuum to a yellow oil
9. 9
   SonstigeThe crude product was purified by preparative layer chromatography (PLC) on a 0.1×20×20 cm silica gel GF plate
10. 10
    ExtraktionThe band at Rf 0.44-0.56 was extracted with EtOAc
11. 11
    Sonstigethe extracts evaporated under vacuum

Vorschrift

A solution of 9a-butyl-7-methoxymethoxy-4-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (162 mg, 0.52 mmol) in anhydrous THF (2.5 mL) was cooled in an ice bath and stirred under a nitrogen atmosphere while 0.4M LDA in THF (1.55 mL, 0.62 mmol) was added by syringe. After stirring at 0° C. for 30 minutes, the solution was cooled to −78° C. (dry ice-acetone bath) and treated with iodomethane (0.162 mL, 2.6 mmol). The resulting mixture was allowed to slowly warm to room temperature, then stirred at room temperature overnight. The mixture was diluted with EtOAc (60 mL) and shaken with saturated aqueous NH4Cl (40 mL). The aqueous phase was extracted with more EtOAc (20 mL). The combined organics were washed with 5% NaHCO3, water, and brine, dried over MgSO4, filtered, and concentrated under vacuum to a yellow oil. The crude product was purified by preparative layer chromatography (PLC) on a 0.1×20×20 cm silica gel GF plate using 4:1 hexanes-EtOAc as developing solvent. The band at Rf 0.44-0.56 was extracted with EtOAc and the extracts evaporated under vacuum to provide (2SR,9aSR)-9a-butyl-2,4-dimethyl-7-methoxymethoxy-1,2,9,9a-tetrahydro-3H-fluoren-3-one (111 mg) as an oil.

Quelle