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| Identifiers | |
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| CAS Number | |
| 3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.011.654 
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| CompTox Dashboard (EPA) | |
InChI
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SMILES
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| Properties | |
| Chemical formula | C10H20 |
| Density | 0,741 g/cm |
| Melting point | 207,2 K (-66.0 °C) |
| Boiling point | 445,2 K (172.0 °C) |
| Related compounds | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).
 Y verify (what is ?)
Infobox references
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Decene is an alkene with the formula C10H20. the molecular weight is 140.26 g/mol. Decene has ten carbon atoms in its parent chain and contains a double bond. It has 20 hydrogen atoms. This article will address decene as the specific constitutional isomer, 1-decene, as well as the broader scope of all possible unsubstituted decenes.
This molecule would be more correctly named as Dec-1-ene, or 1-decene. Although, in IUPAC nomenclature, if a numerical value is not present as a description of the functional group location, then the first position is indicated. Therefore, Decene would be an alkene containing 10 carbon atoms, with a double bond between carbon 1 and 2 (the numbering of double bonds is always given as the lowest possible number, so 2-decene would be a double bond between carbon 2 & 3, 3-decene would include a double bond between carbon 3&4, and so on). Decene, being an alkene of 10 carbon atoms, could be 1, 2, 3, 4, or 5-decene - or written with the numerical value placed immediately prior to the suffix, Dec-5-ene (this type of naming, although correct, is generally reserved to situations when the substitution numbering becomes confusing). There are NO 6-decenes, or 7, 8 9 or 10 for that matter, as substituents must ALWAYS have the lowest possible numerical value, and 10-decene is structurally identical to 1-decene. The double bond may also be at the second, third, fourth or fifth position, in which case the numerical value indicating the first carbon involved in the sigma/pi double bond is essential to proper naming. In addition to describing the location of the double bond, with 2-5 decene one would have to describe the cis/trans isomerism. 1-decene is the only possible isomer of decene that does not exist as a pair of diastereomers. 2-decene, for example, has a double bond between carbon 2 & carbon three, therefore, both carbons are bonded to an alkyl group, and a hydrogen. The pi-bond in a carbon-carbon double bond does not allow for free rotation (which is the case for sigma bonds), so there are two possible orientations. Put very simply, if the alkyl groups (carbon containing substituents) are on the same side of the pi bond, then the compound is said to be a cis diastereomer. A 2-decene compound containing only cis diastereomers would be named cis-2-decene. If the alkyl groups on either side of the double bond are on opposite sides (one up, one down), then it would be named as a trans-2-decene.
Decene, being a mono-unsaturated hydrocarbon will have the chemical formula CnH2n. This basic relationship is true for all monounsaturated hydrocarbons, and for all saturated monocyclic hydrocarbons. In alkanes, the ratio of carbons to hydrogens is CnHn+2.
1-Decene, or any other decene, can be produced in several different ways, but almost all routes involve an elimination as the final step. To produce 1-decene there is a minor obstacle to synthesis, as this is a mono-substituted alkene, the least stable of alkenes. Generally, elimination will favor more substituted products when possible. To avoid the more substituted product (the Zaitseff product), and obtain the Hoffman product, in this care a mono-substituted product, the most common method would be the use of a very "bulky" base, such as (CH3)3COK , potassium tert-butoxide. The concept behind this synthesis is that the tertiary butyl group possesses simply too much space to overcome the steric hindrance necessary to abstract a hydrogen from one of the secondary carbons. Generally, an elimination of a compound such as 2-bromodecane with potassium t-butoxide would result in the t-butoxide abstraction of a hydrogen (H)from the primary carbon, the electrons that formerly formed the bond between the primary carbon and the proton would migrate to the p-orbital of the primary carbon, and overlap with the secondary carbon number 2. These electrons would cause the bond between carbon 2 and the bromine atom to sever (as bromine is an excellent leaving group), resulting in 1-decene, and BrK. Reactions of this variety usually result in 50-60% Hoffman product (1-decene).
The next possible synthesis method would include hydrogenation of 1-decyne, the 1-alkyne homologue of decene. The reaction could be a syn-addition of hydrogen, with Ni2B (aka P-2 catalyst) as a catalyst. Another catalyst that stops hydrogenation at the alkene is Lindlar's catalyst, which produces a syn-addition product. The distinction between syn and anti is not significant in the synthesis of 1-decene as there are two hydrogens on the 1 carbon.
For the synthesis of 2-decene, use of the above catalysts with 2-decyne would yield cis-2-decene. Liquid ammonia and sodium reduction would result in the trans-2 product.
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