STUDIES ON ORGANOSILICON CHEMISTRY .118. SYNTHESIS AND REACTIONS OF METHYL (TRIMETHYLSILYLMETHYL)-ACETYLENECARBOXYLATE - A GENERAL-METHOD FOR THE GENERATION OF DI-EXO-METHYLENEISOXAZOLINES AND NOVEL ACCESS TO FUSED ISOXAZOLES
Methyl (trimethylsilylmethyl)acetylenecarboxylate, which is a common key compound in preparation of precursors for di-exo-methylene derivatives of isoxazolines, reacts with nitrile oxides to yield cycloadducts, isoxazoles. Reduction and acetylation of cycloadducts leading to 4-acetoxymethyl-5-(trimethylsilylmethyl)isoxazoles followed by fluoride ion-promoted 1,4-elimination reaction in the presence of dienophiles gave fused isoxazoles.