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 analogues of strobilurins, 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 methyl (Z)-2-iodo-3-methoxypropenoate and organometallic derivatives such as (1R∗,2R∗)-2-phenylcyclopropylboronic acid and (1R∗,2R)-1-(2-bromozinciophenyl)-2-arylcyclopropanes. The boronic acid has been prepared via cyclopropanation of (E)-2-phenylethenyl-1,3,2-dioxaborinane and the organozinc compounds have been synthesized from easily available (E)-2-bromostilbenes.