Abstract
Complete hydroboration of cyclododecatrienes was reported to give two isomers, depending on conditions. The assignment of their structure had been attempted without unequivocal proofs. We have now used NMR spectroscopy (B-11, C-13, N-15 and Na-23 NMR) to study the sodium amides of these two polycyclic boranes. In addition, one of the isomeric borates could be crystallized, and the X-ray analysis revealed a cis-, cis-, trans configuration of the six-membered rings reversing the original structural assignment.