The Oshima-Utimoto reaction generates 1,3,4-trisubstituted furans with high 1,2-trans-diastereoselectivity and a racemic center at C4. When subjected to catalytic Lewis acid mediated allylation, diastereoenriched product is obtained, with high diastereoinduction when a quaternary center is present at C2.
acetals - allylations - catalysis - heterocycles - stereoselectivity