1,2-OXAPHOSPHOLANES

摘要

2-Oxo-2-alkoxy-5-phosphono-1,2-oxaphospholanes of the formula in which R1 to R7 are hydrocarbon radicals can be prepared from .alpha.,.beta.-unsaturated ketone and 2 or more moles of a dialkylphosphite. Obviously .gamma.-ketophosphonates are intermediates of this reaction as these compounds react with 1 or more moles of dialkylphosphite in yielding the oxaphospholanes too. Both reactions are promoted by alkaline catalysts. The new oxaphospholane derivatives are considerably stable against thermal decomposition. They are compatible with polymeric materials and can be used as flame protecting agent for plastics and resins, for example in polyurethane foams.