Alkadienes alkenes

Alkadienes Alkenes which have two double bonds in their structure. 

Akynes and alkadienes (alkenes with two double bonds) have the general formula C 2n-2-Akenynes (hydrocarbons with one double bond and one triple bond) and alkatrienes (alkenes with three double bonds) have the general formula CnH2n-4, and so forth. 

Our discussion of chemical reactions of alkadienes will be limited to those of conju gated dienes The reactions of isolated dienes are essentially the same as those of individual alkenes The reactions of cumulated dienes are—like their preparation— so specialized that their treatment is better suited to an advanced course m organic chemistry... 

Bivalent radicals derived from unbranched alkenes, alkadienes, and alkynes by removing a hydrogen atom from each of the terminal carbon atoms are named by replacing the endings -ene, -diene, and -yne by -enylene, -dienylene, and -ynylene, respectively. Positions of double and triple bonds are indicated by numbers when necessary. The name vinylene instead of ethenylene is retained for —CH=CH—. 

The scope of haloaliphatic additions to alkenes has been extended to the preparation of 1,2-bis(perfluoroalkyl)iodoethanes by the addition of perfluoroalkyl iodides tofluoroalkyl alkenes [73] (equation 12) or to alkadienes [14] (equation 13)... 

Alkadienes, alkatrienes, and alkatetraenes (poly-enes). These are unsaturated aliphatic hydrocarbons containing two, three, or four C = C double bonds, respectively. Alkadienes are also called diolefins or dienes, and alkatrienes are also known as triolefins or tricncs. Alkenes containing multiple double bonds fall under the general class of poly-enes. Double bonds that alternate with single bonds in a straight chain are said to be conjugated. Examples are... 

Although alkadienes have a higher degree of unsaturation than alkenes, their chemical behavior is similar to alkenes, and their physical properties are similar to alkanes containing the same number of carbon atoms. Common alkenyl groups include... 

Acyclic alkadienes, metathesis of, 134 Acyclic alkenes, metathesis reaction of, 133, 134... 

Wilhoit, R.C., Marsh, K.N., Hong, X., Gadalla, N., Frenkel, M. Densities of Aliphatic Hydrocarbons Alkenes, Alkadienes, Alkynes and Miscellaneous Compounds. 

Alkynes and alkenes with two double bonds (alkadienes) have the general formula... 

The main products of the irradiation of beef fat at high doses are such hydrocarbons as alkanes, alkenes, alkynes, and alkadienes. Of these, the alkanes and alkenes consitute the most significant part of the volatile products. 

Structure effects on the rate of selective or total oxidation of saturated and unsaturated hydrocarbons and their correlations have been used successfully in the exploration of the reaction mechanisms. Adams 150) has shown that the oxidation of alkenes to aldehydes or alkadienes on a BijOj-MoOj catalyst exhibits the same influence of alkene structure on rate as the attack by methyl radicals an excellent Type B correlation has been gained between the rate of these two processes for various alkenes (series 135, five reactants, positive slope). It was concluded on this basis that the rate-determining step of the oxidation is the abstraction of the allylic hydrogen. Similarly, Uchi-jima, Ishida, Uemitsu, and Yoneda 151) correlated the rate of the total oxidation of alkenes on NiO with the quantum-chemical index of delo-calizability of allylic hydrogens (series 136, five reactants). 

Alkynes, moving down the alltane and alkene protocol, and with the formula, CnH2n-2> Have a triple bond between two carbons, such as ethyne, CH CH or bucyne, CH3-CSC-CH3. Confusing the protocol are the dienes, which also have formula, CnH2n-2j but have two double bonds in their molecules such as butadiene (CH2=CH—CH=CH2) or pentadiene, but hardly anyone uses the archaic word alkadiene. 

---