247936-95-4Relevant articles and documents
Does Cycloaddition between Pentafulvene and Cyclopentadiene Take Place?
Niggli, Urs,Neuenschwander, Markus
, p. 2199 - 2208 (2007/10/02)
Reaction of a 1:1 mixture of cyclopentadiene (CPD) and pentafulvene (1a) at 20 deg C gives a complex mixture.The low-molecular-weight part mainly consists of pure and mixed dimers (ca. 73percent) besides corresponding trimers (ca. 20percent) and some corresponding oligomers according to GC/MS investigations (Fig.1).The 3 predominant 'mixed dimers'between CPD and 1a have been separated, and structures 4-6 (Scheme 3) are assigned according to 400- and 600-MHz 1H-NMR investigations.These results show that HOMO(CPD)-LUMO(fulvene) interactions are important in pentafulvene cycloadditions.Dimer 6 results from cycloaddition followed by -H shifts.