1-Hexyne-3-ol reacted with dichloro-phenyl-phosphine yields 1-hexyne-3-yl (3-propylallenyl)-phenyl-phosphinate.Treated with concentrated HCI and ethanol, not only the ester function of the phosphinate is split, but addition of HCl to the allenyl group also occurs and phenyl-(2-chloro-2-hexene-1-yl)-phosphinic acid is obtained (in low yield). The structure of this acid is confirmed by chemical, IR, and NMR data.

The mass spectra and dipole moments of some phenyl-allenyl-phosphinic and allene-phosphonic acids are also presented.