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See: E-Z notation Violet leaf aldehyde, systematic name (E,Z)-nona-2,6-dienal, is a compound having one (E)- and one (Z)-configured double bond. The descriptors (E) (from German entgegen, 'opposite') and (Z) (from German zusammen, 'together') are used to provide a distinct description of the substitution pattern for alkenes, cumulenes or other double bond systems such as oximes.
It can also be named by replacing the "-oic acid" of their corresponding carboxylic acids with "-carbonitrile." The prefix form is "cyano-." Functional class IUPAC nomenclature may also be used in the form of alkyl cyanides. For example, CH 3 CH 2 CH 2 CH 2 C≡N is called pentanenitrile or butyl cyanide.
For straight-chain alkenes with 4 or more carbon atoms, that name does not completely identify the compound. For those cases, and for branched acyclic alkenes, the following rules apply: Find the longest carbon chain in the molecule. If that chain does not contain the double bond, name the compound according to the alkane naming rules. Otherwise:
For example: Markovnikov's rule predicts that the hydrogen atom is added to the carbon of the alkene functional group which has the greater number of hydrogen atoms (fewer alkyl substituents). Zaitsev's rule predicts that the major reaction product is the alkene with the more highly substituted (more stable) double bond.
Adding the hydrogen ion to one carbon atom in the alkene creates a positive charge on the other carbon, forming a carbocation intermediate. The more substituted the carbocation, the more stable it is, due to induction and hyperconjugation. The major product of the addition reaction will be the one formed from the more stable intermediate.
For example, the molecules nitrostyrene and phenethylamine are quite similar; the former can even be reduced into the latter. However, nitrostyrene's α-carbon atom is adjacent to the phenyl group; in phenethylamine this same carbon atom is the β-carbon atom, as phenethylamine (being an amine rather than a styrene) counts its atoms from the ...
This example showcases the "divide and duplicate rule" for double bonds. The vinyl group (C=C) or alkene portion has a higher priority over the alkane (C−C) portion. If an atom, A, is double-bonded to another atom, then atom A should be treated as though it is "connected to the same atom twice". [11]
In organic chemistry, syn-and anti-addition are different ways in which substituent molecules can be added to an alkene (R 2 C=CR 2) or alkyne (RC≡CR).The concepts of syn and anti addition are used to characterize the different reactions of organic chemistry by reflecting the stereochemistry of the products in a reaction.