Cyclononyne


Cyclononyne is an organic compound with the chemical formula. Its molecule has a ring of nine carbon atoms, connected by eight single bonds and one triple bond.

Synthesis

The compound can be prepared by converting 1,2-cyclononanedione to the corresponding dihydrazone via hydrazine and then reacting it with mercuric oxide in the presence of sodium sulfate. When 1,2-cyclononadiene is exposed to light in a dilute pentane solution, it will produce a small amount of cyclononyne and other cycloolefin products via the intermediate isomer of bicyclonon-8-ene. Under the catalysis of a rhodium complex, it is refluxed with sulfur in butanone to obtain a dithiol derivative, which is then refluxed in o-dichlorobenzene and desulfurized to obtain a thiophene derivative.

Physical properties

It is reported that pyrolysis of cyclononyne at 600 °C will lead to forming 1,2,8-nonatriene and trans-bicyclonona-2-ene in a 1:0.9 ratio.