The α-Effect in the Stereochemistry of Kinetic Ketonization of Enols<sup>1</sup><sup>,</sup><sup>2</sup>
作者:Howard E. Zimmerman、Pengfei Wang
DOI:10.1021/jo034732w
日期:2003.11.1
organic reactions. Protonation occurring from the less hindered side of the, e.g., enolic system affords the less stable of two diastereomers. However, one apparent discrepancy has been in the synthesis of prostaglandins. The present research deals with the source of this behavior. A curious effect of the substituent at the enolic alpha carbon was uncovered. In certain instances an alpha substituent is
A palladium-catalyzed conjugate addition of arylboronicacids to α-substituted cyclic enones was developed to give α,β-disubstituted ketones with high diastereoselectivity. Mechanistic investigation showed that the high diastereoselectivity was realized through epimerization.