Highly diastereoselective conjugate addition of organocuprate to acyclic E- and Z-enones: Reversal Stereoselectivity under kinetic and thermodynamic conditions
作者:Keiko Yamamoto、Sachiko Yamada、Kentaro Yamaguchi
DOI:10.1016/s0040-4039(00)60813-4
日期:——
Gilman reagent (lithium dimethylcuprate) adds stereoselectively (98%) to (E)- and (Z)-steroidal 22-en-24-ones to yield 22R-methylated product regardless of the geometry of the enones. The same reagent adds with complete reversal selectivity to the (E)- and (Z)-enones in the presence of TMSCl to yield 22R- and 22S-methyl-24-ketones, respectively.