SYNTHESIS AND CYCLOADDITIONS OF 1-[(TERT-BUTYLDIMETHYLSILYL)OXY]ALKENYL ISOCYANATES

1-[(tert-Butyldimethylsilyl)oxy] alkenyl isocyanates 1a and 1b have be en conveniently prepared from acetyl or propionyl chloride, silver cya nate and tert-butyldimethylsilyl triflate in the presence of triethyla mine. They react with electron-deficient acetylenic dienophiles or wit h tosyl cyanide to give highly functionalised pyridines or derivatives of uracil or thymine in moderate yields. They also cycloadd with 1-(d iethylamino)prop-1-yne, an electron-rich dienophile, to yield glutacon imides and pyridine derivatives.