Building Giant Carbocycles by Reversible C−C Bond Formation

We describe a simple way to build giant macrocyclic hydrocarbons by the reversible formation of carbon–carbon bonds. Specifically, extended spirobifluorene‐substituted derivatives of Wittig's hydrocarbon were synthesized and found to undergo oligomerization, giving the largest hydrocarbon that has been crystallized and characterized by X‐ray diffraction to date. Giant macrocyclic hydrocarbons can be obtained by a facile approach that is based on the reversible formation of carbon–carbon bonds. Extended spirobifluorene‐substituted derivatives of Wittig's hydrocarbon were synthesized and found to undergo oligomerization, leading to the largest hydrocarbon that has been crystallized and characterized by X‐ray diffraction to date.