Chloroboration and allied reactions of unsaturated compounds. Part IX. Organometallic insertion reactions of diketen; synthesis of β-keto-enolates

Abstract

A new general synthesis of β-keto-enolates is described, whereby diketen is caused to react with various organic derivatives of aluminium, boron, and tin. Diketen thus reacts differently from its monomer (which affords C-acetyl derivatives). This is attributed to the unsymmetrical structure of the dimer. The symmetrical phenyl isocyanate dimer behaves similarly to its monomer in its reaction with trisdimethylaminoborane. The β-keto-enolates are characterised by elemental analyses, molecular weights, spectroscopic data (i.r., u.v., n.m.r., and mass spectrometry), and, in some cases, by chemical degradation or alternative methods of synthesis.