One–Pot Synthesis of β,γ-Unsaturated γ-Lactone Phosphorus Yildes using 2-Nitro Trans-Cinnamaldehyde and Acetylenic Esters in the Presence of Triphenylphosphine
Three-component reaction between acetylenic esters, aldehyde semicarbazones and tributyl- or triethyl phosphite leads to stable crystalline phosphite ylides at one step in nearly quantitative yields.
Triphenylphosphine promoted addition of acetylenic esters to benzofuran-2,3-dione: One-pot synthesis of novel γ-spirolactones