Diastereoisomeric 2-diphenylphosphinoyl-1, 3-dioxanes 1–4 were synthesized either via the Arbuzov reaction of isopropyl diphenylphosphinite with (1, 3-dioxan-2-yl) trimethylammonium iodides or via the transacetalization reaction between 1, 3-diols and diphenyl (diethoxymethyl) phosphine oxide. The latter reaction afforded less thermodynamically stable isomers of 3 and 4 in a good yield (44 and 56%, respectively). ...