BF3-Catalyzed Reaction of Cyclobutene-1,2-dione Monoacetal and Its Vinylog with Allylsilanes. Regioselective Synthesis of 4-Allyl-4-ethoxycyclobutenones from Squaric Acid and Their Conversion to Bi-and Tricycloalkanones

Article abstract of DOI:10.1246/cl.1995.525

Regioselective allylation of 2,4- and 4,4-diethoxycyclobuteones was performed with allylsilanes in the presence of BF3*Et2O via a common ethoxycarbenium ion intermediate.A merit of this reaction was demonstrated in an efficient conversion of the obtained