SmI2-promoted intra- and intermolecular C-C bond formation with chiral N-acyl oxazolidinones

The suitability of chiral oxazolidinones in the SmI₂-mediated C-C bond generation between the imide functionality of an N-acyl oxazolidinone unit and an olefinic radical acceptor, in both inter- and intramolecular reactions, was investigated. It was shown that the products from an Evans asymmetric alkylation can undergo direct carbon-carbon bond formation with an acrylamide providing chiral acyclic ketones in reasonable yields. These examples represent the first transformation of such N-acyl oxazolidinones where this chiral auxiliary is removed under the conditions for ketone formation. 5-exo-trig Cyclization studies were also undertaken with the same type of substrates, providing trans-2,5-disubstituted cyclopentanones in yields of approx. 50%. However, attempts to cyclize heteroatom-containing equivalents were less rewarding.