3,3-二乙基戊烷-2,4-二酮 、
2-oxo-2-ethoxy-3,4,5-trimethyl-3-hydroxy-5-diethylphosphono-1,2-oxaphospholane 、
2-oxo-2-ethoxy-3,5-dimethyl-4,4-diethyl-3-hydroxy-5-diethylphosphono-1,2-oxaphospholane 以in each case 35 g of diethylphosphite (0.24 mole) with 0.1 mole of 3-methyl-acetylacetone or 3,3-diethylacetylacetone, then there are obtained 2-oxo-2-ethoxy-3,4,5-trimethyl-3-hydroxy-5-diethylphosphono-1,2-oxaphospholane and 2-oxo-2-ethoxy-3,5-dimethyl-4,4-diethyl-3-hydroxy-5-diethylphosphono-1,2-oxaphospholane的产率得到diethyl phosphite