Abstract
Bis(ω-chloropropyl)dialkoxyphosphonylacetonitriles 4 were established to undergo intramolecular bisdealkylation during distillation affording 6-cyano-2,10-dioxa-1-phosphabicyclo[4.4.0]decane-1-oxide 5 in high yield. The molecular structure of 5 was determined by the single crystal X-ray diffraction method. The molecule consists of cis-fused six-membered rings both in chair conformation.