Reaktionen mit Phosphinalkylenen, XLII. Eine Aufbausequenz für Acetylene aus Carbonsäurechloriden und Phosphonium‐Yliden über 1,2‐Diketone

Abstract

Reactions with Phosphine Alkylenes, XLII. A Sequence for the Preparation of Acetylenes Starting from Carboxylic Chlorides and Phosphorus Ylides via 1,2-Diketones Phosphorus ylides 1 and carboxylic chlorides 2 react with transylidation to give acyl ylides 3 which are oxidized with the adduct of ozone to triphenyl phosphite to yield 1,2-diketones 5. These are converted into the bis(hydrazones) 6 which are oxidized with O2/CuCl in pyridine giving acetylenes 7.