Induction of asymmetry on the [4+3] cycloaddition reaction of C2-functionalized furans

The study of the π-facial diastereoselectivity in the [4+3] cycloaddition reaction of 13 chiral 2-substituted furans with oxyallyl cations is presented. A cis-endo diastereospecificity is observed and the π-facial diastereoselectivity increases by decreasing the distance between the chiral auxiliary and the reactive C2-carbon of the furan ring.