|
Dendralenes General
A dendralene is a discrete acyclic cross-conjugated polyene. The simplest dendralene is buta-1,3-diene (1) or endralene followed by endralene (2), endralene (3) and endralene (4) and so forth. endralene (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 ( endralene) was first prepared in 1955 by pyrolysis of a triacetate: : This compound reacts with two equivalents of maleic anhydride in a tandem DA reaction: : With benzoquinone the reaction product was a linear polymer. Several syntheses of substituted endralenes have been reported, one via an allene, one via a Horner–Wadsworth–Emmons reaction, one via a cross-couplin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Chain Compound
In chemistry, an open-chain compound (also spelled as open chain compound) or acyclic compound (Greek prefix "α", ''without'' and "κύκλος", ''cycle'') is a compound with a linear structure, rather than a cyclic one. An open-chain compound having no side chains is called a straight-chain compound (also spelled as straight chain compound). Many of the simple molecules of organic chemistry, such as the alkanes and alkenes, have both linear and ring isomers, that is, both acyclic and cyclic, with the latter often classified as aromatic. For those with 4 or more carbons, the linear forms can have straight-chain or branched-chain isomers. The lowercase prefix ''n-'' denotes the straight-chain isomer; for example, ''n''-butane is straight-chain butane, whereas ''i''-butane is isobutane. Cycloalkanes are isomers of alkenes, not of alkanes, because the ring's closure involves a C-C bond. Having no rings (aromatic or otherwise), all open-chain compounds are aliphatic. Typically in bioc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
