Diels-Alder Reaction of 5-Triisopropylsilyl-2-vinylfuran and 2-Triethylsilyl-4-vinylfuran.Steric Shielding by the Trialkylsilyl Group.-Vinylfurans bearing sterically demanding trialkylsilyl groups react with dienophiles exclusively via the extraannular mode. -(AVALOS, L. S.; BENITEZ, A.; MUCHOWSKI, J. M.; ROMERO, M.; TALAMAS, F. X.; Heterocycles 45 (1997) 9, 1795-1804; Div. Invest., Syntex S. A. C. V., 62000 Cuernavaca, Morelos, Mex.; EN)