methyl cyclohept-4-ene-1-carboxylate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 180 ml of 16.38% (w/v) aqueous solution of sodium hypochlorite were added slowly at 5° C. over a period of 6 hours while stirring well to a solution of 61.6 g (0.4 mol) of methyl cyclohept-4-enecarboxylate, 62.0 g (0.4 mol) of 4-chlorobenzaldehyde oxime and 0.5 g of tetrabutylammonium bromide in 800 ml of ethyl acetate. The mixture was held at 20° C. for 2 days. The mixture was then filtered and the organic phase was separated and dried over magnesium sulfate. The solvent was removed by evaporation and the residue was crystallized from diethyl ether/hexane to give 44.65 g of methyl 3-(4-chlorophenyl)-3a,5,6,7,8,8a-hexahydro-4H-cyclohept[d]isoxazole-6-carboxylate as a mixture of two diastereoisomers of melting point 150°-185° C. Isomer A has a melting point of 237°-239° C. and isomer B has a melting point of 162°-166° C. The mixture was then filtered the organic phase was separated dried over magnesium sulfate The solvent was removed by evaporation the residue was crystallized from diethyl ether/hexane