Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Reaction of hemiacetal vinylogs 1 with β-halo silyl enol ethers 2 in the presence of baron triflouride etherate yields α-halo 1,5-dicarbonyl compounds 3 . Fonctionalized cyclopropanes 4 are obtained by reaction of diketones 3 in ethanolic potassium hydroxide. ... P. Duhamel, JM Poirier, G. ...