Concept explainers
(a)
Interpretation: The product formed by the thermal electrocyclic ring closure of given triene N is to be determined.
Concept introduction: Electrocyclic reactions are pericyclic reactions which takes place by concerted mechanism. These reactions involve ring opening or ring closure in a conjugated polyene.
(b)
Interpretation: The product formed by the photochemical electrocyclic ring closure of given triene N is to be determined.
Concept introduction: Electrocyclic reactions are pericyclic reactions which takes place by concerted mechanism. These reactions involve ring opening or ring closure in a conjugated polyene.
(c)
Interpretation: The given processes are to be labeled as conrotatory or disrotatory.
Concept introduction: Electrocyclic reactions are pericyclic reactions which takes place by concerted mechanism. These reactions involve ring opening or ring closure in a conjugated polyene. In Conratotory process, the orbitals where rearrangement is taking place rotates in clockwise direction and in disrotatory process the atomic orbitals rotates in opposite direction.
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Organic Chemistry (6th Edition)
- The endiandric acids comprise a group of unsaturated carboxylic acids isolated from a tree that grows in the rainforests of eastern Australia. The methyl esters of endiandric acids D and E have been prepared from polyene Y by a series of two successive electrocyclic reactions: thermal ring closure of the conjugated tetraene followed by ring closure of the resulting conjugated triene. (a) Draw the structures (including stereochemistry) of the methyl esters of endiandric acids D and E. (b) The methyl ester of endiandric acid E undergoes an intramolecular [4 + 2] cycloaddition to form the methyl ester of endiandric acid A. Propose a possible structure for endiandric acid A.arrow_forwardThe endiandric acids comprise a group of unsaturated carboxylic acids isolated from a tree that grows in the rain forests of eastern Australia. The methyl esters of endiandric acids D and E have been prepared from polyene Y by a series of two successive electrocyclic reactions: thermal ring closure of the conjugated tetraene followed by ring closure of the resultingconjugated triene. (a) Draw the structures (including stereochemistry) of the methyl esters of endiandric acids D and E. (b) The methyl ester of endiandric acid E undergoes an intramolecular [4 + 2] cycloaddition to form the methyl ester of endiandric acid A. Propose a possible structure for endiandric acid A.arrow_forward(a) Give an acceptable name for compound A. (b) Draw the organic products formed when A is treated with each reagent: [1] H3O+; [2] −OH, H2O; [3] CH3CH2CH2MgBr (excess), then H2O; [4] LiAlH4, then H2O.arrow_forward
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- (a) (b) HO N N-H Catalytic H+ (-H₂O) ? (c) NH2 HO N (d)arrow_forward(d) When butane, CH3CH2CH2CH3 and bromine gas, Br2 is exposed to sunlight, monobrominated product are produced. The reaction equation is given below: uv CH;CH,CH,CH3 + Br2 A + B (i) State the type of reaction. (ii) What is the function of the sunlight in the reaction? (iii) Draw the structure of monosubstituted products, A and B. Label the major product. (iv) Draw the propagation steps in the mechanism for the formation of the major product.arrow_forward(a) What alkene yields A and B when it is treated with Br2 in CCl4? (b) What alkene yields C and D under the same conditions?arrow_forward
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