Hydroxyl- versus amide-directed cyclopropanation from the allylic position in 1-hydroxy-4-N-acyl-cyclopentenes under modified Simmons-Smith conditions

Article abstract of DOI:10.1016/S0040-4039(96)02425-2

In a functionalized cyclopentene having allylic OH and NH-acyl groups on opposite faces of the ring, the diastereoselective delivery of the incoming methylene group in the diethylzinc version of the Simmons-Smith reaction was completely directed by the NH group. The diastereoselectivity of the reaction can be reversed by complete protection of the amide.