Reaktion #307417

Reaktionsgleichung

trifluoromethanesulfonic acid

propiophenone

phosphorous pentoxide

2-cyclohexen-1-one

→

rac-(1R*,4R*)-5-methyl-6-phenyl-bicyclo[2.2.2]oct-5-en-2-one

Lösungsmittel

NEt3

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas carefully added
2. 2
   Temperaturheated at 40° C. overnight
3. 3
   Sonstigeevaporated to dryness
4. 4
   SonstigePurification by CC with EtOAc-Hept (2:8)

Vorschrift

To a suspension of 0.5 g of phosphorous pentoxide in 30 mL anh. DCM were added 1.3 mL of propiophenone followed by 2.9 mL of 2-cyclohexen-1-one at rt. The suspension was cooled to 0° C. with an ice bath before 2.6 mL of trifluoromethanesulfonic acid was carefully added. The reaction mixture was warmed to rt and then heated at 40° C. overnight. 5.4 mL of NEt3 were dropwise added at 0° C., the mixture was stirred at rt for 10 min and then evaporated to dryness. Purification by CC with EtOAc-Hept (2:8) yielded 1.2 g of rac-(1R*,4R*)-5-methyl-6-phenyl-bicyclo[2.2.2]oct-5-en-2-one as yellow oil.

Quelle