Reagents for Storage and Regeneration of Nonstabilized Azomethine Ylides: Spiroanthraceneoxazolidines.

Abstract

Nonstabilized azomethine ylides are easily trapped by anthraquinone to form stable spiro-oxazolidines, which have an unusual ability to undergo a cycloreversion in the presence of other dipolarophiles at 120-150 °C. All tested recycloadditions with carbonyl compounds and electron-poor alkenes occurred in moderate to high yields (41-92%). Moreover, increasing the reaction temperature to 210 °C made it possible to obtain adducts with low reactive dipolarophiles.