Lab Report 2

For a diels-alder reaction between anthracene and maleic anhydride, are the exo and endo forms of product 9,10-dihydroanthracene-9,10-ɑ,β-succinic acid anhydride different stereoisomers or are they the same molecule?

Following is an example of a type of reaction known as a Diels-Alder reaction 1,3-Pentadiene Ethylene 3-Methylcyclohexene (a racemic mixture) The Diels-Alder reaction between a diene and an alkene is quite remarkable in that it is one of the few ways that chemists have to form two new carbon-carbon bonds in a single reaction. Given what you know about the relative strengths of carbon-carbon sigma and pi bonds, would you predict the Diels-Alder reaction to be exothermic or endothermic? Explain your reasoning.

A hetero Diels-Alder reaction is a variation of the Diels-Alder reaction in which one or more carbon atoms of the diene and/or the dienophile are replaced by other atoms such as oxygen or nitrogen. With this in mind, propose a mechanism consistent with the following transformation in which a multifunctional acyclic reactant produces a macrocyclic (large ring) product. 195°C. 2 Ph Ph- Ph II

The following is an example of a hetero Diels-Alder reaction, because a noncarbon atom (in this case, an N atom) is involved in bond formation and bond breaking. Draw the curved arrows necessary to account for this transformation. OCH3 OCH3 + N- Hydroquinone, benzene, 25 °C, 90 min 86%

The following triene undergoes an intramolecular Diels-Alder reaction to give a bicyclic product. Propose a structural formula for the product. Account for the observation that the Diels-Alder reaction given in this problem takes place under milder conditions (at lower temperature) than the analogous Diels-Alder reaction 0"C Diels-Alder adduct

What is the reaction mechanism of this Diels-Alder reaction between 9-anthracenemethanol and N-methylmaleimide? It is an example of a [4+2]-cycloaddition

As many as 18 different Diels–Alder products can be obtained by heating a mixture of 1,3-butadiene and 2-methyl-1,3-butadiene. Identify the products

1) Sulfolene is a precursor for 1,3-butadiene in this experiment. It reacts by a "cycloreversion" reaction (think reverse Diels-Alder). Draw the mechanism that shows the formation of 1,3- butadiene from sulfolene. 140°C SO2 + 2) Once 1,3-butadiene forms, it can participate in the Diels-Alder reaction. Draw the mechanism for the Diels-Alder reaction. 140°C 3) If you measured the optical rotation of the Diels-Alder product, you would observe no optical activity. Why not? 4) Is it possible to form trans stereoisomer of the product in this experiment? Why or why not?

For the Diels-Alder reaction, identify the diene, the dienophile, and the Diels-Alder adduct. H3CO. R OCH3 LOCH3 R H3CO R compound A compound B compound C Compound A is a: Compound B is a: Compound C is a:

Cyelopenta dicne trans va dimethoxy etham Can anyone show me what a Diels-Alder reaction would look like with cyclopentadiene and trans 1,2 dimethoxyethene? What would be the product? Thank you!

6) The Diels-Alder reaction of anthracene (which is achiral) and maleic anhydride (also achiral) results in the formation of an achiral product. This is not always the case (where two achiral reactants form an achiral product). a) Propose a Diels-Alder reaction where two achiral starting materials result in the formation of a chiral product. b) Would this chiral product be a single enantiomer or a racemic mixture?

BASED ON THIS EXPERIMENT: The purpose of this experiment is to perform a Diels-Alder reaction between E,E-2,4-hexadien-1-ol and maleic anhydride in a "neat" or solventless condition. The Diels-Alder reaction is a [4+2] cycloaddition that forms a six-membered ring, typically a derivative of cyclohexene. The diene, E,E-2,4-hexadien-1-ol, and the dienophile, maleic anhydride, will be mixed and ground together, resulting in a eutectic mixture. The reaction is unique as it occurs without a solvent, contributing to a "greener" experiment. After the reaction, the product will be analyzed through mass measurements, and the mechanism involves a subsequent nucleophilic acyl substitution. QUESTION: how many carbon atoms does a dienophile contribute to the Diels-Alderadduct? How many carbon atoms does a diene contribute? draw andlabel which reagent is the diene, and which is the dienophile.

When anthracene is added to the reaction of chlorobenzene with concentrated NaOH at 350 °C, an interesting Diels–Alderadduct of formula C20H14 results. The proton NMR spectrum of the product shows a singlet of area 2 around d 3 and abroad singlet of area 12 around d 7. Propose a structure for the product, and explain why one of the aromatic rings ofanthracene reacted as a diene

9. For the following Diels-Alder products, propose the correct starting materials needed. D. a. b. C. fo{- ●●● Xox -

What is the product of the following Diels-Alder reactions? +

14

When anthracene is added to the reaction of chlorobenzene with concentrated NaOH at 350 °C, an interesting Diels–Alder adduct of formula C20H14 results. The proton NMR spectrum of the product shows a singlet of area 2 around d 3 and a broad singlet of area 12 around

9. Which of the following dienes could react with acrylonitrile (dienophile in the reaction) in a Diels-Alder reaction? CH, A acrylonitrile B B. pCH, HC C CH Nal 3- Br

Please make your drawings clear! Thank you so much

The following compound undergoes an intramolecular Diels-Alder reaction to give a tricyclic product. Propose a structural formula for the product. heat An intramolecular Diels-Alder adduct

Which molecules can function as dienes in Diels-Alder reactions?