A Chelation-Controlled Ester Enolate Claisen Rearrangement

Article abstract of DOI:10.1021/jo00121a029

The Ireland ester enolate Claisen rearrangement gives rise to Z-trisubstituted alkenes due to heteroatom-enforced control over the conformation of the transition state.An oxygen-bearing functional group at the tetriary carbinol center, which can coordinate to the enolate metal via a seven-membered chelated transition state, provides the control element to explain the selectivity. α,β-Disubstituted unsaturated carboxylic acids are also formed with high diastereoselectivity.