Concept explainers
(a)
Interpretation: The given following compounds has to be prepared using an aldol addition in the first step.
Concept introduction: If two different carbonyl compound used in an aldol addition, known as a crossed-aldol reaction. If the two carbonyl compounds contain alpha carbon then four products are formed because two different enolate ion is formed.
If both carbonyl compounds have alpha hydrogens, primarily only one product is formed if LDA is used to remove the alpha hydrogen from carbonyl carbon that is needed for the enolate ion.
Because LDA is a strong base, all of the carbonyl carbon is converted to the enolate ion, so none of the carbonyl carbon is left behind to react with enolate ion. Therefore, the second carbonyl compound is added slowly.
(b)
Interpretation: The given following compounds has to be prepared using an aldol addition in the first step
Concept introduction: If two different carbonyl compound used in an aldol addition, known as a crossed-aldol reaction. If the two carbonyl compounds contain alpha carbon then four products are formed because two different enolate ion is formed.
If both carbonyl compounds have alpha hydrogens, primarily only one product is formed if LDA is used to remove the alpha hydrogen from carbonyl carbon that is needed for the enolate ion.
Because LDA is a strong base, all of the carbonyl carbon is converted to the enolate ion, so none of the carbonyl carbon is left behind to react with enolate ion. Therefore, the second carbonyl compound is added slowly.
(c)
Interpretation: The given following compounds has to be prepared using an aldol addition in the first step.
Concept introduction: If two different carbonyl compound used in an aldol addition, known as a crossed-aldol reaction. If the two carbonyl compounds contain alpha carbon then four products are formed because two different enolate ion is formed.
If both carbonyl compounds have alpha hydrogens, primarily only one product is formed if LDA is used to remove the alpha hydrogen from carbonyl carbon that is needed for the enolate ion.
Because LDA is a strong base, all of the carbonyl carbon is converted to the enolate ion, so none of the carbonyl carbon is left behind to react with enolate ion. Therefore, the second carbonyl compound is added slowly.
(d)
Interpretation: The given following compounds has to be prepared using an aldol addition in the first step.
Concept introduction: If two different carbonyl compound used in an aldol addition, known as a crossed-aldol reaction. If the two carbonyl compounds contain alpha carbon then four products are formed because two different enolate ion is formed.
If both carbonyl compounds have alpha hydrogens, primarily only one product is formed if LDA is used to remove the alpha hydrogen from carbonyl carbon that is needed for the enolate ion.
Because LDA is a strong base, all of the carbonyl carbon is converted to the enolate ion, so none of the carbonyl carbon is left behind to react with enolate ion. Therefore, the second carbonyl compound is added slowly.
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Chapter 18 Solutions
Organic Chemistry
- Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction observations conclusions ΔΗ is (pick one) A This reaction is faster above 103. °C than below. AS is (pick one) ΔΗ is (pick one) B This reaction is spontaneous only above -9. °C. AS is (pick one) ΔΗ is (pick one) C The reverse of this reaction is always spontaneous. AS is (pick one) 18 Ararrow_forwardUse the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy AS. Note: if you have not been given enough information to decide a sign, select the "unknown" option. reaction observations conclusions A The reverse of this reaction is always spontaneous but proceeds slower at temperatures below 41. °C. ΔΗ is (pick one) AS is (pick one) ΔΗ is (pick one) B This reaction is spontaneous except above 94. °C. AS is (pick one) This reaction is always spontaneous, but ΔΗ is (pick one) C proceeds slower at temperatures below −14. °C. AS is (pick one) Х 00. 18 Ar 무ㅎ B 1 1arrow_forwardDraw the product of the reaction shown below. Ignore inorganic byproducts. + H CH3CH2OH HCI Drawingarrow_forward
- please explain this in simple termsarrow_forwardK Most Reactive Na (3 pts) Can the metal activity series (shown on the right) or a standard reduction potential table explain why potassium metal can be prepared from the reaction of molten KCI and Na metal but sodium metal is not prepared from the reaction of molten NaCl and K metal? Show how (not). Ca Mg Al с Zn Fe Sn Pb H Cu Ag Au Least Reactivearrow_forward(2 pts) Why is O2 more stable as a diatomic molecule than S2?arrow_forward
- Draw the Lewis structure for the polyatomic phosphite (PO¾³¯) a anion. Be sure to include all resonance structures that satisfy the octet rule. C I A [ ]¯arrow_forwardDecide whether these proposed Lewis structures are reasonable. proposed Lewis structure Is the proposed Lewis structure reasonable? Yes. :0: Cl C C1: 0=0: : 0 : : 0 : H C N No, it has the wrong number of valence electrons. The correct number is: ☐ No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:* ☐ Yes. No, it has the wrong number of valence electrons. The correct number is: ☐ No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:* Yes. ☐ No, it has the wrong number of valence electrons. The correct number is: ☐ No, it has the right number of valence electrons but doesn't satisfy the octet rule. The symbols of the problem atoms are:* | * If two or more atoms of the same element don't satisfy the octet rule, just enter the chemical symbol as many times as necessary. For example, if two oxygen atoms don't satisfy the octet rule, enter "0,0".arrow_forwardDraw the Lewis structure for the polyatomic trisulfide anion. Be sure to include all resonance structures that satisfy the octet rule. с [ ] - Garrow_forward
- 1. Calculate the accurate monoisotopic mass (using all 1H, 12C, 14N, 160 and 35CI) for your product using the table in your lab manual. Don't include the Cl, since you should only have [M+H]*. Compare this to the value you see on the LC-MS printout. How much different are they? 2. There are four isotopic peaks for the [M+H]* ion at m/z 240, 241, 242 and 243. For one point of extra credit, explain what each of these is and why they are present. 3. There is a fragment ion at m/z 184. For one point of extra credit, identify this fragment and confirm by calculating the accurate monoisotopic mass. 4. The UV spectrum is also at the bottom of your printout. For one point of extra credit, look up the UV spectrum of bupropion on Google Images and compare to your spectrum. Do they match? Cite your source. 5. For most of you, there will be a second chromatographic peak whose m/z is 74 (to a round number). For one point of extra credit, see if you can identify this molecule as well and confirm by…arrow_forwardPlease draw, not just describe!arrow_forwardcan you draw each step on a piece of a paper please this is very confusing to mearrow_forward
Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning