Iodoenolcyclization of 2-allyl substituted beta-keto esters under thermodynamic conditions

摘要

An improved procedure for the synthesis of diastereo-enriched tetrasubstituted 4,5-dihydrofurans by using I_2-induced enolcyclization of beta-keto esters is reported.The reactions using I_2 in anhydrous MeCN are considered under thermodynamic control and the more stable trans isomers are preferentially produced.