1. Predict the relative rates for the reaction of butadiene and a. ethene, b. methyl propenoate, c. and maleic acid
2. what product is expected from the reaction of fumaric acid (trans-2-butenedioic acid) with 1,3-butadiene.
c>b>a but you will need to explain why.
2. I have recently answered on here. I will post the date.
see Friday, February 27, 2009 at 12:27am
To predict the relative rates of reactions, we need to consider factors such as reaction mechanism, reactant stability, and reaction conditions. Since the question does not provide any specific details about these factors, we can make some general predictions based on the reactivity of the reactants.
1. Predicting relative rates of reaction:
a. Ethene: Ethene is a simple alkene with two carbon atoms. It does not contain any functional groups or substituents besides the double bond. In general, the reactivity of simple alkenes like ethene is moderate. The rate of reaction can be influenced by the reaction conditions, such as temperature and catalysts.
b. Methyl propenoate: Methyl propenoate is an ester containing a double bond. Ester groups are generally less reactive compared to simple alkenes due to the electron-withdrawing nature of the carbonyl group. The methyl group attached to the ester can increase the reactivity to some extent. However, the overall reactivity of methyl propenoate is expected to be slower than that of ethene but faster than that of maleic acid.
c. Maleic acid: Maleic acid is a dicarboxylic acid with two carboxyl groups and a double bond. The presence of the carboxyl groups makes it more polar and electron-withdrawing, which can reduce its reactivity compared to simpler alkenes. The double bond can participate in conjugation, making maleic acid more stable compared to other reactants. Considering these factors, maleic acid is expected to have the slowest reaction rate among the three compounds.
Please note that these rate predictions are general and can vary depending on specific reaction conditions.
2. Predicting the product from the reaction of fumaric acid with 1,3-butadiene:
The reaction of fumaric acid (trans-2-butenedioic acid) with 1,3-butadiene is a Diels-Alder reaction, which is a type of cycloaddition reaction. In this reaction, the diene (1,3-butadiene) reacts with the dienophile (fumaric acid) to form a cyclic compound.
The reactants undergo a concerted reaction, where the four electrons in the diene system and the two electrons in the dienophile participate in the formation of two new sigma bonds and the breaking of their respective pi bonds.
The product formed from this reaction is called a bicyclic compound and is known as the Diels-Alder adduct. The specific structure of the adduct can vary depending on the stereochemistry of the reactants. In this case, since fumaric acid is a trans isomer, the product will be a cis-fused bicyclic compound.
Again, note that the specific conditions of the reaction, such as temperature, solvent, and catalyst, can influence the product distribution, so it's always important to consider these factors in a real-life scenario.