By reaction of hydrogen peroxide and bis(diphenylphosphino)ethane in acetone, the 1∶2 adduct (bis(diphenylphosphinoyl)ethane)·2(2,2-dihydroperoxypropane) (dppeO2)· 2[Me2C(OOH)2], stabilized by H-bonding between Me2- C(OOH)2 and dppeO2, was rapidly obtained in high yields in the presence of R2SnCl2 (R = Me or Bun).
