Neue Synthese von α‐verzweigten β‐Ketoestern

Reactions of phosphorus ylides with acyl chlorides: pathways and preparative potential

“…Ph3P CHR 1 2 16 A similar reaction of acyl chlorides with phosphoranes 3 containing the ester group, followed by cathodic reduction of acylated phosphonium chlorides 5, provides a method to obtain esters of a-substituted b-oxo acids 6. 17 Monosubstituted alkylidenephosphoranes 2 containing a hydrogen atom at the ylide carbon are conjugated bases, whereas the corresponding phosphonium salts are acids. The position of equilibrium depends on the nature of substituents R 1 and R 2 and is strongly (often, almost completely) shifted to the right if R 1 is a much stronger electron-withdrawing group than R 2 ; in fact, this is the case in acylation reactions.…”

Die Hydrolyse des 1, 1, 3, 3‐Tetrakis(dimethylamino)‐1λ5, 3λ5‐diphosphets

“…Hydrolyseprodukte sind Verbindungen der allgemeinen Formel 4. Der analogen Hydrolysereaktion unterliegen offenkettige Akzeptor-substituierte Phosphorylide [7]. L 1 Eine andere Verbindung des Typs 3 (R' = N(i-C,H,&, R2 = R3 = C6H,) wird dagegen Wir untersuchten die Hydrolyse von 2 im einzelnen.…”