Enantiomerically Pure Vinylcyclopropylboronic Esters

Abstract

Abstract Vinylcyclopropanes are versatile intermediates and products in organic synthesis. The corresponding enantiomerically pure boronic esters should lead to highly flexible building blocks with a variety of applications. A detailed study towards the selective synthesis of ( E )‐ and ( Z )‐vinyl derivatives starting from the known diastereo‐ and enantiopure cyclopropylmethanols 3 and 4 is presented. The boronic esters were activated via their trifluoroboronates; the optimization of the reaction is discussed. The endeavour culminated in the synthesis of (–)‐(1 S ,2 S )‐dictyopterene A ( 38 ). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)