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a Diels-Alder reaction. Alkenes add to dienes to give cyclohexenes. This conversion is an example of a Diels-Alder reaction. Such reaction proceed with retention of stereochemistry. The rates are sensitive to electron-withdrawing or electron-donating substituents. When irradiated by UV-light, alkenes dimerize to give cyclobutanes. [20]
There are two types of alpha-olefins, branched and linear (or normal). The chemical properties of branched alpha-olefins with a branch at either the second (vinylidene) or the third carbon number are significantly different from the properties of linear alpha-olefins and those with branches on the fourth carbon number and further from the start of the chain.
In organosulfur chemistry, the thiol-ene reaction (also alkene hydrothiolation) is an organic reaction between a thiol (R−SH) and an alkene (R 2 C=CR 2) to form a thioether (R−S−R'). This reaction was first reported in 1905, [ 1 ] but it gained prominence in the late 1990s and early 2000s for its feasibility and wide range of applications.
In organic chemistry, the ene reaction (also known as the Alder-ene reaction by its discoverer Kurt Alder in 1943) is a chemical reaction between an alkene with an allylic hydrogen (the ene) and a compound containing a multiple bond (the enophile), in order to form a new σ-bond with migration of the ene double bond and 1,5 hydrogen shift.
Such reactions are subject to the usual parameters that affect other reactions in coordination chemistry, but steric effects are especially important in determining the stereochemistry and regiochemistry of the reactions. The reverse reaction, the de-insertion of CO and alkenes, are of fundamental significance in many catalytic cycles as well.
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.
An example is the ozonolysis of eugenol converting the terminal alkene to an aldehyde: [9] By controlling the reaction/workup conditions, unsymmetrical products can be generated from symmetrical alkenes: [10] Using TsOH; sodium bicarbonate (NaHCO 3); dimethyl sulfide (DMS) gives an aldehyde and a dimethyl acetal
In organic chemistry, alpha-elimination refers to reactions of this type: [1] R 2 CHX → R 2 C: + HX. The reaction is employed to generate carbenes and nitrenes. The formation of dichlorocarbene from chloroform is an example. Alpha eliminations contrasts with beta eliminations, which are commonly used to generate alkenes: R 2 CHCXR' 2 → R 2 ...