Although the thermal decomposition of the unsubstituted silacyclobutane has been studied by several only in the original work of Sommer and co-workers was a silicon-containing product identified. Evidence for the parent silene, anticipated from the 2+ 2 fragmentation of silacyclobutane, was based on the isolation of a product from addition of a silicon-oxygen u bond across the silicon-carbon P bond (eq 1). We report here that
