Abstract
Abstract: 3,4-Bisphosphono- 1,2,4,5-hexatetraenes, prepared from the reaction of chlorophosphine/phosphite with 2,4-hexadiyne-1,6-diols,underwent an intramolecular [2+2]-cycloaddition to form 1,2-bis(diethylphosphonyl)-3,4- bis(isopropyleny1)cyclobutene.