作者:Klaus Saitmacher、Jochen E. Schulz、Martin Nieger、Fritz Vögtle
DOI:10.1039/c39920000175
日期:——
The fourfold clamped title hydrocarbon 5, the biphenylene unit of which is strongly deformed out of plane, was obtained in 13% yield via sulfone pyrolysis; the X-ray analysis demonstrates that the framework of the biphenylene unit is bent out of planarity up to 18.7° due to transannular repulsioon, whereas the C–C bonds of the four ethano bridges are elongated compared with reference compounds.