In 1978 we observedl the probable formation of [4. ll] propellane (1). The recent acquisition of a microprobe for I3C NMR determinations has enabled us to obtain further evidence sup- porting this claim. In view of the current interest in [nll] propellanes, 24 we offer our observations at this time. In particular, we find chemical shift values in the I3C NMR spectrum which are remarkably different from those reported earlier4 for the closely ...