Concept explainers
(a)
Interpretation:
Each step in the mechanism of the acid-catalysed interconversion of (R)-and (S)-
Concept introduction:
In acid catalysed keto-enol tautomerism, the carbonyl oxygen is protonated by an acid. In the next step, deprotonation occurs at the alpha carbon to give the enol form. This is applicable on most of the proton-transfer mechanisms.
(b)
Interpretation:
A mechanism for the isomerization that occurs when cis-
Concept introduction:
In base catalysed keto-enol tautomerism, the proton is removed from the alpha carbon. In the next step, reprotonation occurs at oxygen to give a vinyl alcohol (enol form).
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Organic Chemistry (9th Edition)
- Galantamine, a natural product produced by the amaryllis family of flowering plants, has been used in the early treatment of Alzheimer's disease. In a synthesis of galantamine and related compounds (J. Org. Chem. 2015, 80, 1952-1956), compound 1 was converted into compound 2. Propose an efficient synthesis for the conversion of 1 to 2 A. NaOH MeO D. DMP or PCC G. HBr MeO B. H₂SO4, H₂O, HgSO4 E. Na2Cr₂O7, H₂SO4, H₂O H. 1) O3; 2) DMS H 2 The conversion of 1 to 2 can be performed with some reagent or combination of the reagents listed below. Give the necessary reagents in the correct order for each transformation, as a string of letters (without spaces or punctuation, such as "EBF"). If there is more than one correct solution, provide just one answer. C. 1) BH3-THF; 2) H₂O2, NaOH F.HBr, ROOR I. TsCl, py Meo I₁, N Me Galanthamine OHarrow_forwardGalantamine, a natural product produced by the amaryllis family of flowering plants, has been used in the early treatment of Alzheimer's disease. In a synthesis of galantamine and related compounds (J. Org. Chem. 2015, 80, 1952-1956), compound 1 was converted into compound 2. Propose an efficient synthesis for the conversion of 1 to 2 A. NaOH MeO D. DMP or PCC G. HBr 1 MeO B. H₂SO4, H₂O, HgSO4 E. Na₂Cr₂O7, H₂SO4, H₂O H. 1) O3; 2) DMS H 2 x I. TsCl, py The conversion of 1 to 2 can be performed with some reagent or combination of the reagents listed below. Give the necessary reagents in the correct order for each transformation, as a string of letters (without spaces or punctuation, such as "EBF"). If there is more than one correct solution, provide just one answer. C. 1) BH3-THF; 2) H₂O2, NaOH F.HBr, ROOR = MeO Ill. N Me Galanthamine OHarrow_forwardPyrethroids are insecticides that target the nervous systems of insects. They have found widespread use because they have low toxicity to mammals and readily degrade in the environment. Consider the synthesis route of the following pyrethroid. X CCl₂ CCl4 Cl3C 2 eq. MeO a. Outline a probable mechanism for converting X to Y b. Suggest a reason for the regioselectivity of the formation of Y Zarrow_forward
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- What is the mechanisms to get from the reactant to the productsarrow_forwardAdd any remaining curved arrows to draw the mechanism for the formation of Barrow_forward3. For each of the reactions below, redraw the alkyl halide with the correct stereochemistry as indicated and provide mechanisms with explanations to account for the products observed. OCH, a. CH,OH R-enantiomer Racemic mixture b. NaCN H3C-Ç-CH2CH3 H3C-C-CH2CH3 Acetone CN Br R-enantiomer S-enantiomcr HIC HICarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningOrganic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning