Synthetic approaches to a fluorinated tetrahedrane

Approaches to tetrakis(2-chlorotetrafluoroethyl)tetrahedrane (2) from 1,6-dichlorooctafluoro-3-hexyne (4) have been explored. The synthesis and chemistry are described of cyclopropenyl ketenimines (6a,b), a Dewar thiophene (24) and a cyclobutadienetricarbonyliron complex (33) derived from this acetylene.