title: 2D 1H and 13C NMR evidences of the [2 + 2] autodimerization of 2-benzyl-5-benzylidene cyclopentanone yielding two different diphenyl, dispiro cyclobutane derivatives.
abstract: The ene-ene [2 + 2] cycloaddition of 2-benzyl-5-benzylidenecyclopentanone proceeds smoothly and spontaneously in benzene-d6 or deuteriochloroform solution to give two different diphenyl dispiro [4.1.4.1] dodecan-4,11-diones. Detailed 1H and 13C 2DNMR spectroscopy (COSY, HMQC, HMBC) were performed in order to prove the existence in solution of two cyclobutane derivatives, one a previously described photodimer obtained by the UV irradiation of crystals of 2-benzyl-5-benzylidenecyclopentanone.
authors.affiliation: Instituto de Química, Universidad Nacional Autónoma de México, C. U. Coyoacán, México DF. maudiaz@servidor.unam.mx
authors.forename: E
authors.initials: E
authors.lastname: Díaz
authors.forename: H
authors.initials: H
authors.lastname: Barrios
authors.forename: D
authors.initials: D
authors.lastname: Corona
authors.forename: A
authors.initials: A
authors.lastname: Guzmán
authors.forename: R
authors.initials: R
authors.lastname: Díaz
authors.forename: A
authors.initials: A
authors.lastname: Fuentes
mesh_terms: D002247:Carbon Isotopes; D003503:Cyclobutanes; D003517:Cyclopentanes / Q000737:chemistry*; D019281:Dimerization; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010636:Phenols; D013141:Spiro Compounds
chemical_list: D002247:Carbon Isotopes; D003503:Cyclobutanes; D003517:Cyclopentanes; D010636:Phenols; D013141:Spiro Compounds; D006859:Hydrogen