Question

In: Chemistry

1. The dehydrohalogenation of dibromostilbene occurs through two stages. Why does the second stage in particular...

1. The dehydrohalogenation of dibromostilbene occurs through two stages. Why does the second stage in particular require so much energy to complete?

2. How do the substituents on the diene and the dienophile affect the rate of reaction in a Diels-Alder reaction?

Solutions

Expert Solution

the activation energy for the generation of a vinyl cation intermediate would be higher than that for a lower energy intermediate. This is illustrated for alkenes versus alkynes by the following energy diagrams.

The energy level diagram of vinyl cation intermediate which very higher energy than the other alkyl cation intermediate. At the second step of dehydrohalogenation produce intermediate which is higher energy like carbocation intermediate so for that it required strong base to deprotonation.


Related Solutions

identify stages of production why a firm will not produce either in stage 1 or stage...
identify stages of production why a firm will not produce either in stage 1 or stage 3? explain briefly
CATABOLISM OF CARBOHYDRATED CAN BE DIVIDED INTO 4 MAIN STAGES Stage 1 is ___________ which occurs...
CATABOLISM OF CARBOHYDRATED CAN BE DIVIDED INTO 4 MAIN STAGES Stage 1 is ___________ which occurs in the __________-. At the end of stage 1 Carbohydrates have been converted to ______________. Stage 2 for monosaccharides is formation of pyruvate which occurs in the ________. Formation of pyruvate from glucose is called ________________. Under aerobic conditions, pyruvate moves to the mitochondria where it is converted to ____________, resulting in fewer ATP being produced. Stage 3: involves a cycle of chemical reactions....
A rocket is launched straight up. It contains two stages (Stage 1 and Stage 2) of...
A rocket is launched straight up. It contains two stages (Stage 1 and Stage 2) of solid rocket fuel that are designed to burn for 10.0 and 5.0 s, respectively, with no time interval between them. In Stage 1, the rocket fuel provides a net upward acceleration of 18 m/s2. In Stage 2, the net upward acceleration is 13 m/s2. Neglecting air resistance, calculate the maximum altitude above the surface of Earth of the payload and the time required for...
Kohlberg believed that individual's progressed through six stages of development and that during this stage an...
Kohlberg believed that individual's progressed through six stages of development and that during this stage an individual is willing to disobey the law if they believe it violates their own ethical principles. A Stage 2 B Stage 5 C Stage 3 D Stage 6
1) A reciprocating compressor has two stages with inlet air going into LP stage at 1...
1) A reciprocating compressor has two stages with inlet air going into LP stage at 1 bar, 16°C and at the rate of 12 m3/min. Air is finally delivered at 7 bar and there is perfect intercooling at optimum pressure between the stages. The index for compression is 1.25 and compressor runs at 600 rpm. Neglecting clearance volume determine intermediate pressure and total power required. 2) A reciprocating compressor of single stage and double acting type has free air delivered...
A gas expands from point A to B. The expansion consists of two stages. Stage 1)...
A gas expands from point A to B. The expansion consists of two stages. Stage 1) The gas expands at constant pressure from 15 to 39 litres. Stage 2) The gas expands from 31 litres to 82 litres with a pressure drop according to the equation; P = 100 - 0.8 V kPa Calculate the work done on the gas.
What are the stages the membrane potential goes through during an action potential? Describe each stage...
What are the stages the membrane potential goes through during an action potential? Describe each stage in terms of the changes in sodium and potassium ions inside the cell. Name and describe the two types of refractory periods, and what, if anything would make a neuron fire during a refractory period.
1. Describe in depth the three phases of the first stage of delivery, second stage, third...
1. Describe in depth the three phases of the first stage of delivery, second stage, third stage, and fourth stage of the delivery?
What are the six stages in the selling process? What role does each stage play?
What are the six stages in the selling process? What role does each stage play?
What are the 6 stages in the selling process? What role does each stage play?
What are the 6 stages in the selling process? What role does each stage play? Which stage do you believe is most important? Why?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT