cis- and trans-3,5-Diethoxy-1-oxa-3,5-diphosphorinane-3,5-dione

The title compounds, cis- and trans-C₇H₁₆O₅P₂, display chair conformations of the heterocyclic rings, with much larger absolute torsion angles around C—O—C (> 72°) than around P—C—P (< 47°). Ring angles are lower than tetrahedral at phosphorus, but higher at carbon and oxygen, with a maximum of 116.03 (12)° for the P—C—P angle of the cis isomer. Several C—H...O contacts, including one as short as H...O = 2.27 Å, can be classified as hydrogen bonds.

-1