Abstract
AbstractThe configuration of the spiro centre in polycyclic compounds containing a spiro[4.4]nonane substructure is analyzed in terms of symmetry coordinates. As revealed by X‐ray structures of such compounds, the local distortions around the quaternary C‐atom are dominated by a decrease of the ring‐bond angles at the spiro centre and a twist of one ring relative to the other. The planoid deformations given by the planarization index PC are comparatively small for spiro[4.4]nonanes, which contain either no additional bridges between the rings or only α,β′–or β,β′‐polymethylene bridges. This indicates that the local strain in the spiro C(C)4 fragments is rather small.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
