Hydrochloric Acid → HCID 21465100, compound

Participants

Reaction Steps

Slowly add 2-phenylethyl bromide (2.6 g) to a slurry of Mg (0.37 g) in THF (50 mL) and heat at reflux for 4 h. Cool the solution to ambient temperature and add to a solution of ethyl 4-oxo-cyclo-hexanecarboxylate (2.4 g) in THF (50 mL). After 2 h, pour the reaction mixture into a half-saturated solution of NH4Cl and extract with EtOAc. Partially purify the product on a silica gel column, eluting with EtOAc. Dissolve the product in toluene (100 mL), treat with p-TsOH and heat at reflux overnight with azeotropic removal of water. Cool the reaction mixture, wash with saturated NaHCO3 solution and concentrate. Purify the crude product on a silica gel column, eluting with CH2Cl2 to obtain ethyl 4-(2-phenylethyl)-cyclohex-3-enecarboxylate (0.45 g) and 1-(2-phenyl-ethyl)-2-oxabicyclo[2.2.2]octan-3-one (0.71 g). Dissolve 1-(2-phenyl-ethyl)-2-oxabicyclo[2.2.2]octan-3-one in EtOH, treat with conc.HCl (catalytic) and heat at reflux overnight. Dilute the reaction mixture with water and extract with EtOAc. Concentrate the organic layer to obtain additional ethyl 4-(2-phenylethyl)-cyclohex-3-enecarboxylate (0.88 g).

Provenance & Evidence