Which molecule, C or D, will react faster with ethane in a Diels-Alder reaction is to be explained. Concept introduction: The [4+2] cycloaddition reactions are generally known as a Diels-Alder reaction. A Diels-Alder reaction involves a diene and a dienophile. A diene shares four π electrons from the two conjugated π bonds while a dienophile shares two p electrons from a single π bond. The Diels-Alder reaction is concerted and proceeds through a six-membered aromatic transition state. For a Diels-Alder reaction to occur, the diene must be present in the s-cis conformation because both ends of the diene must be relatively close to the dienophile in the transition state. s indicates that the cis designation describes the orientation of groups about a single bond, rather than a double bond or the plane of the ring. The s-trans conformation of the diene is more stable than s- cis conformation due to steric repulsion. Thus, the conformer which easily undergoes s-cis form will react readily with a dienophile.

Question

Want to see the full answer?

Answer 1

Question

Chapter 24, Problem 24.4P

Interpretation Introduction

Interpretation:

Which molecule, C or D, will react faster with ethane in a Diels-Alder reaction is to be explained.

Concept introduction:

The [4+2] cycloaddition reactions are generally known as a Diels-Alder reaction. A Diels-Alder reaction involves a diene and a dienophile. A diene shares four π electrons from the two conjugated π bonds while a dienophile shares two p electrons from a single π bond. The Diels-Alder reaction is concerted and proceeds through a six-membered aromatic transition state. For a Diels-Alder reaction to occur, the diene must be present in the s-cis conformation because both ends of the diene must be relatively close to the dienophile in the transition state. s indicates that the cis designation describes the orientation of groups about a single bond, rather than a double bond or the plane of the ring. The s-trans conformation of the diene is more stable than s- cis conformation due to steric repulsion. Thus, the conformer which easily undergoes s-cis form will react readily with a dienophile.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

Identify the unknown compound from its IR and proton NMR spectra. C4H6O: 'H NMR: 82.43 (1H, t, J = 2 Hz); 8 3.41 (3H, s); 8 4.10 (2H, d, J = 2 Hz) IR: 2125, 3300 cm¹ The C4H6O compound liberates a gas when treated with C2H5 MgBr. Draw the unknown compound. Select Draw с H Templates More

Please help with number 6 I got a negative number could that be right?

1,4-Dimethyl-1,3-cyclohexadiene can undergo 1,2- or 1,4-addition with hydrogen halides. (a) 1,2-Addition i. Draw the carbocation intermediate(s) formed during the 1,2-addition of hydrobromic acid to 1,4-dimethyl-1,3-cyclohexadiene. ii. What is the major 1,2-addition product formed during the reaction in (i)? (b) 1,4-Addition i. Draw the carbocation intermediate(s) formed during the 1,4-addition of hydrobromic acid to 1,4-dimethyl-1,3-cyclohexadiene. ii. What is the major 1,4-addition product formed from the reaction in (i)? (c) What is the kinetic product from the reaction of one mole of hydrobromic acid with 1,4-dimethyl-1,3-cyclohexadiene? Explain your reasoning. (d) What is the thermodynamic product from the reaction of one mole of hydrobro-mic acid with 1,4-dimethyl-1,3-cyclohexadiene? Explain your reasoning. (e) What major product will result when 1,4-dimethyl-1,3-cyclohexadiene is treated with one mole of hydrobromic acid at - 78 deg * C ? Explain your reasoning.