(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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ORGANIC CHEMISTRY
- H H H H 4. In each row, rank the dienophiles in decreasing order of reactivity in a Diels-Alder reaction. Most reactive = 1, least reactive = 4. a a H CH3 H CH3 H₂C H OHC H b b H CH3 H CN H NC H NC C C CN H CH3 H H H H H d d CHO H CHO Harrow_forwardе. Sn1 SN2 E1 E2 Initial Stereochemistry = R ОН H,C-CH2 -CH- -CH3 + H3РО4 Product/Stereochemistry(ies) of reaction earrow_forwardShow 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_forward
- H ОНС H H CH3 H CHO H CH3 CN NC H H H a b d Rank these dienophiles in decreasing order of reactivity in the Diels-Alder reaction. Most reactive = 1, least reactive =4.arrow_forward11. Choose the major product. e (A) o (B) (C) xxx t Od 12. Choose the major product. TVEN meo meo hv ull 'CH mes A "CN mo 원 CN med Twarrow_forward2. Assign the stereochemistry of the following eight compounds as either R or S. H CI H HO Br HO Br CI H CI- A H E .OH Br B F Br с HO Br G CI H H Br' H Darrow_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_forwarda. What product is obtained from the reaction of HCl with 1-butene? With 2-butene? b. Which of the two reactions has the greater free energy of activation? c. Which compound reacts more rapidly with HCl: (Z)-2-butene or (E)-2-butene?arrow_forwardDraw the product (including stereochemistry) formed from each pair of reactants in a thermal [4 + 2] cycloaddition reaction.arrow_forward
- In 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_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_forward9. Which of the following dienes could react with acrylonitrile (dienophile in the reaction) in a Diels-Alder reaction? CH, A acrylonitrile B B. pCH, HC C CH Nal 3- Brarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning