Stereocontrolled synthesis of carbon-carbon double bond locked analogues of strobilurins which are characterized by a trans-1,2-disubstituted cyclopropane ring

The racemic forms of four new carbon-carbon double bond locked analogs of strobilurins, e.g. I, which are characterized by a trans-1,2-disubstituted cyclopropane ring, have been synthesized according to a strategy which involves palladium-catalyzed cross-coupling reactions between Me (Z)-2-iodo-3-methoxypropenoate and organometallic derivs. such as (1R*,2R*)-2-phenylcyclopropylboronic acid and (1R*,2R*)-1-(2-bromozinciophenyl)-2-arylcyclopropanes. The boronic acid has been prepd. via cyclopropanation of (E)-2-phenylethenyl-1,3,2-dioxaborinane and the organozinc compds. have been synthesized from easily available (E)-2-bromostilbenes.