REACTION OF ACYLSILANES WITH SULFUR YLIDES - SELECTIVE FORMATION OF SILYL ENOL ETHERS OR BETA-KETOSILANES

The reaction of acylsilanes with sulfur ylides in THF results in the f ormation of the corresponding silyl enol ethers or beta-ketosilanes. T he relative ratio of these products varies with the ylide conditions a nd the stability of ylide used. It is noteworthy that silyl enol ether s were formed under the salt-free ylide conditions, and that beta-keto silanes were yielded in the presence of soluble inorganic salts in THF , selectively. The formation of both products would be interpreted in terms of the anionotropic and cationotropic rearrangements of silyl gr oup in the reaction intermediate.