1-Vinyl-4-methyl-2,6,7-trioxabicyclo(2.2.2)octanes: Unsaturated Homoenolate Anion Equivalents.

Abstract The metalation of (E)-1-(2-chlorovinyl)- or (E)-1-(2-bromovinyl)-4-methyl-2,6,7-trioxabicyclo[2.2.2]octane with tert-butyllithium produced an unsaturated homoenolate anion equivalent which intercepted alkyl halides, aldehydes, ketones, and lactones to afford β-alkylated or β-acylated orthoesters, which, in turn, furnished β-substituted acrylate esters.