Search results
Results From The WOW.Com Content Network
Crotyl groups attached to R. A crotyl group is an organic functional group with the formula RCH 2 CH=CHCH 3. [1] Systematically, it is called a but-2-en-1-yl group and exhibits geometric isomerism, being either cis (Z) or trans (E).
But-2-ene is an acyclic alkene with four carbon atoms. It is the simplest alkene exhibiting cis/trans-isomerism (also known as (E/Z)-isomerism); that is, it exists as two geometric isomers cis-but-2-ene ((Z)-but-2-ene) and trans-but-2-ene ((E)-but-2-ene). It is a petrochemical, produced by the catalytic cracking of crude oil or the dimerization ...
This image of a simple structural formula is ineligible for copyright and therefore in the public domain, because it consists entirely of information that is common property and contains no original authorship.
Because the cis–trans and E–Z systems compare different groups on the alkene, it is not strictly true that Z corresponds to cis and E corresponds to trans. For example, trans-2-chlorobut-2-ene (the two methyl groups, C1 and C4, on the but-2-ene backbone are trans to each other) is (Z)-2-chlorobut-2-ene (the chlorine and C4 are together ...
Formula Boiling pt (°C) ... trans-2-Butene: CH 3 CH=CHCH 3: 0.9 −43.3 ... Ethenol 557-75-5 10.5° = vinyl alcohol (tautomerizes) 1,1,1,2,2,3,4,4,4-nonafluorobutane ...
For example, of the isomers of butene, the two methyl groups of (Z)-but-2-ene (a.k.a. cis-2-butene) appear on the same side of the double bond, and in (E)-but-2-ene (a.k.a. trans-2-butene) the methyl groups appear on opposite sides. These two isomers of butene have distinct properties.
Simple cis and trans isomers may be indicated with a prefixed cis-or trans-: cis-but-2-ene, trans-but-2-ene. However, cis-and trans-are relative descriptors. It is IUPAC convention to describe all alkenes using absolute descriptors of Z-(same side) and E-(opposite) with the Cahn–Ingold–Prelog priority rules (see also E–Z notation).
In the chemical structures above, the small blue numbers in the structure images are the numbering of the atoms in the main backbone chain of the molecules. Other organic compounds have the formula C 4 H 8 , namely cyclobutane and methylcyclopropane , but are not alkenes and do not fall under the name butene .