Interpretation:
The observation that cyclohexadecaoctaene isomerizes to two different isomers depending on reaction conditions is to be explained indicating whether each reaction is conrotatory or disrotatory.
Concept introduction:
An electrocyclic reaction involves the cyclization of a conjugated acyclic system. These reactions are reversible and are highly stereospecific.
In elecrocyclic reactions involving even number of electron pairs, a thermal reaction occurs in conrotatory manner and a photochemical reaction occurs in disrotatory manner.
In elecrocyclic reactions involving odd number of electron pairs, a thermal reaction occurs in disrotatory manner and a photochemical reaction occurs in conrotatory manner.
To explain:
The observation that cyclohexadecaoctaene isomerizes to two different isomers depending on reaction conditions.
To indicate:
Whether each reaction is conrotatory or disrotatory.
Trending nowThis is a popular solution!
Chapter 30 Solutions
Organic Chemistry
- Nonconjugated , -unsaturated ketones, such as 3-cyclohexenone, are in an acid-catalyzed equilibrium with their conjugated , -unsaturated isomers. Propose a mechanism for this isomerization.arrow_forwardWhen 2-iodo-1,4-dimethylcyclohexane is heated in acetic acid, CH3COOH, a mixture of substitution and elimination products is obtained. Provide structures for all possible products, writing [not drawing] the name of the mechanism by which each one is formed.arrow_forwardPredicts the major products for the following reaction.arrow_forward
- When tert-butyl bromide is heated with an equal amount of ethanol in an inert solvent, one of the products is ethyl tert-butyl ether. (a) What happens to the reaction rate if the concentration of ethanol is doubled?arrow_forwardExplain this observation: Ethyl 3-phenylpropanoate (C6H5CH2CH2CO2CH2CH3) reacts with electrophiles to afford ortho- and para-disubstituted arenes, but ethyl 3-phenylprop-2-enoate (C6H5CH=CHCO2CH2CH3) reacts with electrophiles to afford meta- disubstituted arenes.arrow_forwardIdentify products A and B from the given 1H NMR data. Treatment of acetone [(CH3)2C=O] with dilute aqueous base forms B. Compound B exhibits four singlets in its 1H NMR spectrum at 1.3 (6 H), 2.2 (3 H), 2.5 (2 H), and 3.8 (1H) ppm. What is the structure of B?arrow_forward
- Rank the compounds in each of the following groups in order of their reactiv- ity to electrophilic substitution: (b) Phenol, benzene, chlorobenzene, benzoic acid (c) Benzene, bromobenzene, benzaldehyde, anilinearrow_forward5-Hydroxyhexanal forms a six-membered cyclic hemiacetal, which predominates at equilibrium in aqueous solution. (a) Draw a structural formula for this cyclic hemiacetal. (b) How many stereoisomers are possible for 5-hydroxyhexanal? (c) How many stereoisomers are possible for this cyclic hemiacetal? (d) Draw alternative chair conformations for each stereoisomer and label groups axial or Also predict which of the alternative chair conformations for each stereoisomer is more stable.arrow_forwardWhen acetonitrile is treated with concentrated sulfuric acid and tert-butanol, followed by water, a product is formed whose 'H NMR spectrum exhibits the following three signals: singlet, 1.3 ppm, 9 H; singlet, 2.0 ppm, 3 H; and broad singlet, 8.2 ppm, 1 H. Its IR spectrum exhibits one broad absorption of medium intensity between 3300 and 3500 cm-1, and a narrow, intense absorption near 1650 cm¯1. A key intermediate is shown. Draw the structure of the product, and draw the complete, detailed mechanism for the reaction. CH3 CH3 H2SO4 (conc) H2O ? + H3C H3C H3C-C=Ñ-c `CH3 CH3 HOarrow_forward
- Give the products for each of the following reactions. (a) (b) (c) + H₂cod OCH3 о || -COCH 3arrow_forward11:43 Q1. (a) (c) (d) (b) Two stereoisomers of but-2-ene are formed when 2-bromobutane reacts with ethanolic potassium hydroxide. (i) Explain what is meant by the term stereoisomers. Library Name and outline a mechanism for the reaction of 2-bromo-2-methylpropane with ethanolic potassium hydroxide to form the alkene 2-methylpropene, (CH3)2C=CH₂ Name of mechanism Mechanism (ii) Draw the structures and give the names of the two stereoisomers of but-2-ene. Stereoisomer 1 Name (iii) Name this type of stereoisomerism. Select Name Stereoisomer 2 When 2-bromo-2-methylpropane reacts with aqueous potassium hydroxide, 2-methylpropan-2-ol is formed as shown by the following equation. CH3 H₂C-C-CH3 + KOH Br Page 2 of 14 CH3 H3C-C-CH3 + KBr ОН State the role of the hydroxide ions in this reaction. Write an equation for the reaction that occurs when CH3CH₂CH₂CH₂Br reacts with an excess of ammonia. Name the organic product of this reaction. Equation Name of product 9,284 Photos, 1,166 Videos For You…arrow_forwardMustard gas, Cl¬CH2CH2¬S¬CH2CH2¬Cl, was used as a poisonous chemical agentin World War I. Mustard gas is much more toxic than a typical primary alkyl chloride. Itstoxicity stems from its ability to alkylate amino groups on important metabolic enzymes,rendering the enzymes inactive.(a) Propose a mechanism to explain why mustard gas is an exceptionally potent alkylatingagentarrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning