Concept explainers
(a)
Interpretation:
The structure of diethyl malonate showing acidic hydrogens is to be stated. The reason as to why it is more acidic than ordinary ester is to be stated.
Concept introduction:
Acidic hydrogen is defined as hydrogen that carries positive charge when the acid dissociates. The acidity in esters depends upon the stability of enolate ion. The higher is the stability of enolate ion higher is the acidity.
Answer to Problem 22.1P
The structure of the diethyl malonate showing acidic hydrogens is given below.
The diethyl malonate is more acidic than ordinary ester because its conjugate base is stabilized by delocalization of negative charge as shown below.
Explanation of Solution
In diethyl malonate the methylene group is surrounded by two carbonyl groups as shown below.
Figure 1
This active hydrogen is abstracted by base and generates a negative charge. The negative charge is delocalized between carbon and oxygen. This delocalization stabilizes the enolate ion. However, the presence of two carbonyl group increases the polar effect and stabilize the enolate ion. The diethyl malonate is more acidic than ordinary ester as its conjugate base is stabilized by delocalization of negative charge.
The acidity of the carbonyl compound is directly proportional to the stability of the enolate ion. The conjugate base stabilized by delocalization of diethyl malonate is shown below.
Figure 2
The structure of the diethyl malonate showing acidic hydrogens is given in Figure 2. The diethyl malonate is more acidic than ordinary ester due to delocalization of negative charge in its conjugate base.
(b)
Interpretation:
The structure of ethyl acetoacetate showing acidic hydrogens is to be stated. The reason as to why it is more acidic than ordinary ester is to be stated.
Concept introduction:
Acidic hydrogen is defined as hydrogen carry positive charge when the acid dissociates. The acidity in esters depends upon the stability of enolate ion. The higher is the stability of enolate ion higher is the acidity.
Answer to Problem 22.1P
The structure of ethyl acetoacetate showing acidic hydrogens is given below.
The ethyl acetoacetate is more acidic than ordinary ester because its conjugate base is stabilized by delocalization of negative charge as shown below.
Explanation of Solution
In ethyl acetoacetate, the methylene group is surrounded by two carbonyl groups as shown below.
Figure 3
This active hydrogen is abstracted by base and generates a negative charge. The negative charge is delocalized between carbon and oxygen. This delocalization stabilizes the enolate ion. However, the presence of two carbonyl groups increases the polar effect and stabilize the enolate ions. The conjugate base stabilized by delocalization of ethyl acetoacetate is shown below.
Figure 4
The ethyl acetoacetate is more acidic than ordinary ester as its conjugate base is stabilized by delocalization of negative charge.
The structure of ethyl acetoacetate is shown in Figure 3 and the acidic character of ethyl acetoacetate is shown in Figure 4.
Want to see more full solutions like this?
Chapter 22 Solutions
Organic Chemistry, Ebook And Single-course Homework Access
- Polymers may be composed of thousands of monomers. Draw three repeat units (trimer) of the polymer formed in this reaction. Assume there are hydrogen atoms there are hydrogen atoms on the two ends of the trimer. Ignore inorganic byproducts please.arrow_forwardi need help with the folarrow_forwardPLEASE HELP NOW! URGENT!arrow_forward
- a. Determine whether each of the Followery Molecules is in the R- On the y- Configuration 1-01"/ 1-6-4 Br 4 I el Br b. Draw The Fisher projection For all the Meso compounds that can exist FOR The Following molenlearrow_forward1- Refer to the monosaccharides below to answer each of the following question(s): CH₂OH CHO CH₂OH CH₂OH 0 H- OH 0 0 HO- H H- -OH HO H HO H H OH HO- H CH₂OH H. OH HO H HO- H CH₂OH CH₂OH CH3 a. Sorbose b. Rhamnose c. Erythrulose d. Xylulose Classify each sugar by type; for example, glucose is an aldohexose. a. Xylulose is .. b. Erythrulose is . c. Sorbose is .. d. Rhamnose is .. 2- Consider the reaction below to answer the following question(s). CHO H OH CH₂OH CH₂OH HO- H HO HO + H. -OH HO OH HO. H OH OH H -OH H OH CH₂OH Q Z a. Refer to Exhibit 25-11. Place a triangle around the anomeric carbon in compound Q. Compound Z is: b. 1. the D-anomer. 2. the a-anomer. 3. the ẞ-anomer. 4. the L-anomer. c. Which anomer is the LEAST stable? d. Q and Z are cyclic examples of: a. acetals b. hemiacetals c. alditols d. hemialditolsarrow_forwardi need help identifying the four carbon oxygen bonds in the following:arrow_forward
- Imagine each of the molecules shown below was found in an aqueous solution. Can you tell whether the solution is acidic, basic, or neutral? molecule HO H3N + The solution is... X O acidic OH O basic H3N-CH-C-O O neutral ○ (unknown) O acidic ○ basic CH2 CH 3-S-CH2 O neutral ○ (unknown) H3N O OH O acidic O basic Oneutral O (unknown) 0 H3N-CH-C-O CH3 CH CH3 O acidic O basic O neutral ○ (unknown) ? olo Ar BHarrow_forwardno Ai walkthroughs need other product (product in picture is wrong dont submit the same thing)arrow_forwardHow to solve this!arrow_forward
Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage Learning