Resumo

FERNANDEZ, Mario; RAMIREZ, Alejandro; HERNANDEZ, Ramón  e  ORDONEZ, Mario. Evidence for a Strained Cyclic Allene in the Ring Closure Reaction of Enynylketenes. Rev. Soc. Quím. Méx [online]. 2002, vol.46, n.2, pp.136-139. ISSN 0583-7693.

We show in this paper using HF and MP2 ab initio calculations that the ring closure of 5 generates an intermediate best described as the closed-shell cyclic allene 6a, instead of the usually assumed diradical nature reported in the literature. This intermediate then gives rise to the formation of 7. The closed-shell cyclic allene nature of the lowest-lying singlet was confirmed using CASSCF calculations.

Palavras-chave : cyclic allene; Hartree-Fock; MP2; CASSCF; benzoquinones.

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