Heterocycles by cycloaddition. Part 7. Cycloaddition reactions of mesoionic dithiolones with fulvenes
Abstract
The reactions of fulvenes with several mesoionic compounds have been investigated. The mesoionic dithiolones (7) gave regio- and stereo-selective [4π+ 2π] cycloadducts (11)–(13) across the endocyclic double bonds of fulvenes, but no periselectivity was observed with unsymmetrical fulvenes. Several other mesoionic ring systems failed to react or gave complex reaction products.