Stereoregulated synthesis of unsaturated compounds Communication 9. Stereochemistry of the reactions of aldehydes with ?,?-unsaturated triphenylphosphonium ylides [alkylidenetriphenylphosphoranes

Abstract

1. A study was made of the effect of the polarity of the medium and the nature of the halide ions on steric orientation in “carbonyl-olefination” with the aid ofβ,γ-unsaturated triphenylphosphonium ylides. 2. The conditions were found which made it possible to use the carbonyl-olefination reaction for the stereospecific synthesis of trans-trans and trans-cis dienes.