Notice what this accomplishes: the C α -C β linkage no longer involves a pi-bond (because C β is now sp 3 -hybridized!) and thus is free to rotate - and it does, by 180 o . After rotation is complete,...Notice what this accomplishes: the C α -C β linkage no longer involves a pi-bond (because C β is now sp 3 -hybridized!) and thus is free to rotate - and it does, by 180 o . After rotation is complete, the Michael enolate simply collapses, reforming the C α -C β pi-bond in the trans configuration and eliminating GSH.
