(a)
Interpretation: The product of given electrocyclic reaction is to be drawn.
Concept introduction: Electrocyclic reactions involve ring opening or ring closure in a conjugated polyene. According to Woodward-Hoffmann rules, the polyene containing even number of bonds in thermal conditions undergoes reaction in conrotatory fashion and polyene containing odd number of bonds undergo reaction in disrotatory fashion.
(b)
Interpretation: The product of given electrocyclic reaction is to be drawn.
Concept introduction: Electrocyclic reactions involve ring opening or ring closure in a conjugated polyene. According to Woodward-Hoffmann rules, the polyene containing even number of bonds in photochemical conditions undergoes reaction in disrotatory fashion and polyene containing odd number of bonds undergo reaction in conrotatory fashion.
(c)
Interpretation: The product of given electrocyclic reaction is to be drawn.
Concept introduction: Electrocyclic reactions involve ring opening or ring closure in a conjugated polyene. According to Woodward-Hoffmann rules, the polyene containing even number of bonds in thermal conditions undergoes reaction in conrotatory fashion and polyene containing odd number of bonds undergo reaction in disrotatory fashion.
(d)
Interpretation: The product of given electrocyclic reaction is to be drawn.
Concept introduction: Electrocyclic reactions involve ring opening or ring closure in a conjugated polyene. According to Woodward-Hoffmann rules, the polyene containing even number of bonds in photochemical conditions undergoes reaction in disrotatory fashion and polyene containing odd number of bonds undergo reaction in conrotatory fashion.
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Chapter 27 Solutions
Package: Loose Leaf for Organic Chemistry with Biological Topics with Connect Access Card
- Show the product of the Diels–Alder reaction of the following diene with 3-buten-2-one, H2C = CHCOCH3. Make sure you show the full stereochemistry of the reaction product.arrow_forwardDraw the major product for each reaction. Be sure to use wedges or hashes to show stereochemistry when the reaction is stereoselective. You may draw the product after the first step if you do not know the second step. HO. OH OH 1. Br₂, hv 2. CH₂ONA, CH₂OH 1. MsCl, py 2. CH,CH,ONa, CH3CH₂OH 1. Nal, acetone 2. NaSH, DMSO 1. HBr 2. NaN₂ A B D 4arrow_forwardPlease help with 4 A-Darrow_forward
- m. SN1 SN2 E1 E2 CH3CH2CH2CH2-OH + POCI3 with pyridine Product(s) of reaction m.arrow_forwardPropose a structure for the likley rearrangement that is more stable.arrow_forwardIn 4+2 cycloaddition, ENDO stereochemistry is preferred because: endo stereochemistry allows the diene to adopt s-cis conformation. endo stereochemistry results in less steric hindrance. the transition state leading to endo stereochemistry is higher energy. it allows for additional π to π overlap between the diene and the dienophile.arrow_forward
- Draw the products of the following Diels–Alder reactions. Indicate stereochemistry where appropriate and show the pushing mechanism for a and barrow_forwardUsing the Woodward–Hoffmann rules, predict the stereochemistry of eachreaction.a. a [6 + 4] thermal cycloadditionb. photochemical electrocyclic ring closure of deca-1,3,5,7,9-pentaenec. a [4 + 4] photochemical cycloadditiond. a thermal [5,5] sigmatropic rearrangementarrow_forwardName the following compound: Br O (1S, 3S,4R)-1-chloro-3-bromo-4-isopropylcyclohexane O (1R, 2R, 5R)-1-bromo-2-isopropyl-5-chlorocyclohexane O (1R, 2S, 4R)-2-bromo-4-chloro-1-isopropylcyclohexane O (1S, 25, 4R)-2-bromo-4-chloro-1-isopropylcyclohexane O (15, 25, 5R)-1-bromo-2-isopropyl-5-chlorocyclohexanearrow_forward
- PAOLLE D 9. А 10. OMe OMe B C CO₂Me CO₂Me A+Y C+W NHCOCH3 W A+X D+Y B+Z N-Ph COMe Y 11 ||| IV V 8. Rank the dienophiles numbered W to Z in order of decreasing reactivity in a typical Diels- Alder reaction. Z Rank the dienes numbered A to D in order of decreasing reactivity in a typical Diels-Alder reaction Arrange the combinations numbered I to V in order of decreasing HOMO-LUMO gap (largest to smallest gap).arrow_forwardWhat is the most likely product, I, II, III, IV, of the following reaction with correct stereochemistry?arrow_forwardWhich statement is true? Options: A: Upon photo-excitation y4 is the LUMO of the pentadienyl anion. Upon photo-excitation y2 is the LUMO of the allyl cation. Upon photo-excitation y4 is the SOMO of butadiene. B: С: D: Upon photo-excitation w4 is the LUMO of the pentadienyl cation. E: Upon photo-excitation y4 is the LUMO of the 1,3,5-hexatriene.arrow_forward
Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning