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A dendralene is a discrete acyclic cross-conjugated polyene.〔Henning Hopf, ''Classics in Hydrocarbon Chemistry'', Wiley VCH, 2000.〕 The simplest dendralene is buta-1,3-diene (1) or ()dendralene followed by ()dendralene (2), ()dendralene (3) and ()dendralene (4) and so forth. ()dendralene (butadiene) is the only one not cross-conjugated. : The name ''dendralene'' is pulled together from the words dendrimer, linear and alkene. The higher dendralenes are of scientific interest because they open up a large array of new organic compounds from a relatively simple precursor especially by Diels-Alder chemistry. Their cyclic counterparts are aptly called radialenes. ==Synthesis== Vinylbutadiene (()dendralene) was first prepared in 1955 by pyrolysis of a triacetate:〔 〕 :Vinyl butadiene synthesis Baily 1955 This compound reacts with two equivalents of maleic anhydride in a tandem DA reaction: :Reaction vinylbutadiene maleic anhydride With benzoquinone the reaction product was a linear polymer. Several syntheses of substituted ()dendralenes have been reported, one via an allene,〔 Mieko Arisawa, Takumichi Sugihara and Masahiko Yamaguchi ''Synthesis of cross-conjugated trienes by dimerization of allenes with palladium-phenol catalyst'' ''Chem. Commun.'' 1998; 2615-2616 〕 one via a Horner–Wadsworth–Emmons reaction,〔Rekha Singh and Sunil K. Ghosh ''Synthesis of substituted ()dendralenes and their unique cycloaddition reactions'' ''Chem. Commun.'' 2011; Advance Article 〕 one via a cross-coupling reaction 〔 〕 and one from an allylic carbonate.〔Kassem Beydoun, Hui-Jun Zhang, Basker Sundararaju, Bernard Demerseman, Mathieu Achard, Zhenfeng Xi and Christian Bruneau ''Efficient ruthenium-catalyzed synthesis of ()dendralenes from 1,3-dienic allylic carbonates'' ''Chem. Commun.'' 2009; 6580-6582 〕 One synthetic route to ()dendralene starts from chloroprene. This compound is converted to a Grignard reagent by action of magnesium metal which is then reacted with copper(I) chloride to an organocopper intermediate which is in turn dimerized using copper(II) chloride in an oxidative coupling reaction to give the butadiene dimer called ()dendralene. : The ()-dendralene compound was reported in 2009:〔''Practical Synthesis of the Dendralene Family Reveals Alternation in Behavior'' Alan D. Payne, Gomotsang Bojase, Michael N. Paddon-Row, and Michael S. Sherburn Angew. Chem. Int. Ed. 2009, 48, 〕 : in a successive Kumada–Tamao–Corriu coupling and Negishi coupling. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dendralene」の詳細全文を読む スポンサード リンク
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