Meta,para andmeta,ortho double exo nucleophilic additions of trimethylsilylester enolates derived from saturated and unsaturated carboxylic acids to tricarbonylchromium complexes of arylethers:dearomatizing cyclization to lactoones

摘要

Potassium enolates derived from saturatd and bis9trimethylsilyl)ketene acene acetals react with tricarbonylchromiumcomplexes of anisole and diphenylether to give,in addition to #alpha#-arylcarboxylic acids,the mono adducts,lactones,arising from a double exo nucleophilic addition.The latter were not observed in the case of benzenetricarbonylchromium.The intermediate of thenature of the substitutents on the ketene acetals,of the nature of the oxidant,and of the nature of the oxidant,and of the nature of the ester enolates on the course of the reaction has been established and will be discussed.