Interpretation:
When 2-methyl-2-propenal is treated with allyl magnesium chloride (H2C=CH-CH2-MgCl) in ether, then with dilute aqueous acid, a compound A is obtained, which, when heated strongly, yields an
Concept introduction:
Sigmatropic reaction can be described as the migration of allylic sigma bond at one end of the π-electron system to the other end of the π-electron system as an uncatalyzed intramolecular reaction. In some cases, Lewis acid catalysts can also be applied. Though, the position of π-bond is changed in Sigmatropic reaction, the total number of π-bonds remain unchanged. The sigma bond can be cleaved at the middle or at the end of the π-system. The formation of sigma bond at 3, 3-position of a 1, 5-diene is called as cope rearrangement. Notably, [3, 3] sigmatropic reaction of allyl vinyl ether is termed as Claisen rearrangement.
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Organic Chemistry
- (S)-2-butanol reacts with potassium dichromate (K2CrO4) in aqueous sulfuric acid to give A(C,HgO). Treatment of A with ethylmagnesium bromide in anhydrous ether gives B(C,H140). Draw the structure of B.arrow_forwardGrignard reagent is a versatile tool in synthetic organic chemistry. Using bromocyclopentane as a starting material, show how a Grignard reagent, X, is synthesized. Reaction of X with water produces compound Y while treatment in carbon dioxide followed by hydrolysis forms compound Z. 3-methyl-2butanone reacts with X and hydrolyses to yield compound AA. Draw the structural formulae of compounds Y, Z and AA and write the chemical equations respectively.arrow_forwardTreatment of cis-4-bromocyclohexanol with HO– affords compound A and cyclohex-3-en-1-ol. Treatment of trans-4- bromocyclohexanol under the same conditions forms compound B and cyclohex-3-en-1-ol. A and B contain different functional groups and are not isomers of each other. Propose structures for A and B and offer an explanation for their formation.arrow_forward
- Compound X (molecular formula C10H12O) was treated with NH2NH2, -OH to yield compound Y (molecular formula C10H14). Based on the 1H NMR spectra of X and Y given below, what are the structures of X and Y?arrow_forward2-bromo-2-methylbutane undergoes hydrolysis reaction with water, H2O toform compound W. Compound X and compound Y are produced when 2-bromo-2-methylbutane undergoes elimination reaction with alcoholic ofsodium hydroxide, NaOH. (ii) What is the type of reaction involved in the formation of compound W? (iii) Identify the major product of the elimination reaction between compound Xand compound Y based on Zaitsev’s rule.arrow_forwardAn unknown compound A (molecular formula C7H14O) was treated with NaBH4 in CH3OH to form compound B (molecular formula C7H16O). Compound A has a strong absorption in its IR spectrum at 1716 cm−1. Compound B has a strong absorption in its IR spectrum at 3600–3200 cm−1. The 1H NMR spectra of A and B are given. What are the structures of A and B?arrow_forward
- Compound A of molecular formula C8H14 is reduced by sodium in liquid ammonia to give compound B of molecular formula C8H16. product (Y).Both A and B undergo hydrogenation in the presence of a platinum catalyst to give 2,5-dimethylhexane. Ozonolysis of B with an oxidative workup produces a carboxylic acid of molecular formula C4H8O2. Reaction of B with a peroxyacid gives a chiral C8H14O product, but reaction with bromine gives an achiral C8H14Br2 product. What are the identities of A and B?arrow_forwardIdentify compounds A, B, and C. a. Compound A has molecular formula C8H12 and reacts with two equivalents of H2. A gives HCOCH2CH2CHO as the only product of oxidative cleavage with O3 followed by CH3SCH3. b. Compound B has molecular formula C6H10 and gives (CH3)2CHCH2CH2CHCH3 when treated with excess H2 in the presence of Pd. B reacts with NaNH2 and CH3I to form compound C (molecular formula C7H12).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
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- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning