Acetylene Equivalent for Bay Region Diels-Alder Cycloaddition

Significance

Nitroethylene is generated in situ by the dehydration of 2-nitroethanol with phthalic anhydride. This active dienophile usually gives thermally stable Diels-Alder adducts that do not lose the nitro group. However, when reacted with perylene (1), the bay region is converted into an unsubstituted benzene ring. Bisanthene 3, which is used as a model compound for the carbon nanotube bay regions, gives a double Diels-Alder ­cycloadduct in good yield.