Cycloaddition reactions of ethyl (E)- and (Z)-3-fluoropropenoate

Ethyl (Z)-3-fluoropropenoate (Z-5) has been prepared in a pure state in 68% yield by a Wittig procedure developed by Burton. Ethyl (E)-3-fluoropropenoate (E-6) was prepared in 38% yield following the synthetic method of Purrington. The Z isomer gives cycloaddition with 1,3-diphenylisobenzofuran and cyclopentadiene to give a product with completely endo configurations. The E isomer also gives cycloadducts with same dienes to give mixtures of endo and exo products.

Ethyl (Z)-3-fluoropropenoate (Z-5) has been prepared in a pure state in 68% yield by a Wittig procedure developed by Burton. Ethyl (E)-3-fluoropropenoate (E-6) was prepared in 38% yield following the synthetic method of Purrington. The Z isomer gives cycloaddition with 1,3-diphenylisobenzofuran and cyclopentadiene to give a product with completely endo configurations. The E isomer also gives cycloadducts with same dienes to give mixtures of endo and exo products.Figure optionsDownload as PowerPoint slideHighlights
► A new procedure for the preparation of ethyl (Z)-3-fluoropropenoate has been developed.
► Both ethyl (Z)-3-fluoropropenoate and ethyl (E)-3-fluoropropenoate have been allowed to participate in Diels–Alder cycloadditions with both 1,3-diphenylisobenzofuran and cyclopentadiene.
► The Z isomer adds in each case to give a cis product with endo stereochemistry. The E isomer adds in each case to give the trans isomer with no stereoselectivity.