Development of a new source of alkylcarbenes allows the direct formation of homocuban-9-ylidene. Deuteriomethanol traps not only the carbene, but the product of its rearrangement, the bridgehead alkene homocub-1(9)-ene. Together with the earlier observation that the bridgehead alkene rearranged to the carbene this demonstrates the first example of an equilibrating carbene-bridgehead alkene pair.