Asymmetrical [4+2]-Cycloaddition of (-)-Menthyl Acrylate and (-)-Menthyl Methacrylate to Cyclopentadiene in the Presence of BBr3

An asymmetrical synthesis of bicyclo2.2.1]hept-2-enes is described performed by 4+2]-cyclo-addition of (-)-menthyl acrylate, (-)-menthyl methacrylate to cyclopentadiene in the presence of BBr₃.The effect of different factors on isomer composition, yield, and enantiomeric purity of the compoundsobtained was investigated. Kovatch indices were determined and boiling points were estimated with the use of gas-liquid chromatography.