Reaction of Cyclic Silyl Phosphites with Haloacetones

The reaction of cyclic silyl phosphites (2) with haloacetones (3) was in vestigated. When oxirane compounds were used as scavengers of trimethylsily halides, cyclic acetonylphosphonates (4) were obtained directly. Treatment of 2-trimethylsilyloxy-1, 3, 2-dioxaphosphorinane (2a) with bromoacetone (3b) or iodoacetone (3c) in propylene oxide gave 4a in 24% and 41% yields, respectively. With cyclohexane oxide, the reaction of 2a with 3c in MeCN at reflux gave 4a in 50% yield. Treatment of 5, 5-dimethyl-2-trimethylsilyloxy-1, 3, 2-dioxaphosphorinane (2b) with 3c in the same manner gave 4b in 43% yield.