The reaction of cyclic silyl phosphites (2) with haloacetones (3) was investigated When oxiranc compounds were used as scavengers of trimethylsilyl halides, cyclic acetonylphosphonates (4) were obtained directly. Treatment of 2—trimethylsi1yloxy-1, 3, 2- dioxaphosphorinane (2a) with bromoacetone (3b) or iodoacetone (3c) in propylene oxide gave 43 in 24% and 41% yields, respectively. With cyclohexanc oxide, the reaction of 2a ...