Concept explainers
(a)
Interpretation: The product formed when the given compound in Problem 27.6 undergoes photochemical electrocyclic ring opening or ring closure is to be predicted. The given process is to be labeled as conrotatory or disrotatory. The stereochemistry around tetrahedral stereogenic centers and double bonds is to be indicated.
Concept introduction: Electrocyclic reactions involve the conversion of
Curved arrows aid in determining the movement and flow of electrons in the reaction. The electrons that take part in the
Answer to Problem 27.8P
The product formed in the given photochemical electrocyclic ring closure reaction is
Explanation of Solution
The thermal electrocyclic ring closure reaction is shown below.
Figure 1
Electrocyclic reactions involve the conversion of
Under photochemical condition, conrotatory process takes place in the given reaction. The orientation of substituents and stereochemistry around tetrahedral stereogenic centers and double bonds in the given reaction are shown below.
Figure 2
The conrotatory process involves the rotation of two orbitals in the same direction. The reaction in above figure implies that orbitals move in the same direction in the reactant molecule and the formation of trans product occurs. One methyl group is present above the plane and one methyl group is present below the plane in the product. Therefore, the product formed in the given photochemical electrocyclic ring closure reaction is
The product formed in the given photochemical electrocyclic ring closure reaction is
(b)
Interpretation: The product formed when the given compound in Problem 27.6 undergoes photochemical electrocyclic ring opening or ring closure is to be predicted. The given process is to be labeled as conrotatory or disrotatory. The stereochemistry around tetrahedral stereogenic centers and double bonds is to be indicated.
Concept introduction: Electrocyclic reactions involve the conversion of
Curved arrows aid in determining the movement and flow of electrons in the reaction. The electrons that take part in the chemical reactions are shown by the curved arrows.
Answer to Problem 27.8P
The product formed in the given photochemical electrocyclic ring opening reaction is
Explanation of Solution
The thermal electrocyclic ring opening reaction is shown below.
Figure 3
Electrocyclic reactions involve the conversion of
Under photochemical condition, disrotatory process takes place in the given reaction. The movement of substituents and stereochemistry around tetrahedral stereogenic centers and double bonds in the given reaction are shown below.
Figure 4
The disrotatory process involves the rotation of two orbitals in the opposite direction. The reaction in above figure implies that orbitals move in the opposite direction in the reactant molecule and the formation of trans product occurs. One methyl group is present above the plane and one methyl group is present below the plane in the product shows the stereochemistry. Therefore, the product formed in the given photochemical electrocyclic ring opening reaction is
The product formed in the given photochemical electrocyclic ring opening reaction is
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Chapter 27 Solutions
Organic Chemistry
- Another standard reference electrode is the standard calomel electrode: Hg2Cl2(s) (calomel) + 2e2 Hg() +2 Cl(aq) This electrode is usually constructed with saturated KCI to keep the Cl- concentration constant (similar to what we discussed with the Ag-AgCl electrode). Under these conditions the potential of this half-cell is 0.241 V. A measurement was taken by dipping a Cu wire and a saturated calomel electrode into a CuSO4 solution: saturated calomel electrode potentiometer copper wire CuSO4 a) Write the half reaction for the Cu electrode. b) Write the Nernst equation for the Cu electrode, which will include [Cu2+] c) If the voltage on the potentiometer reads 0.068 V, solve for [Cu²+].arrow_forward2. (Part B). Identify a sequence of FGI that prepares the Synthesis Target 2,4-dimethoxy- pentane. All carbons in the Synthesis Target must start as carbons in either ethyne, propyne or methanol. Hint: use your analysis of Product carbons' origins (Part A) to identify possible structure(s) of a precursor that can be converted to the Synthesis Target using one FGI. All carbons in the Synthesis Target must start as carbons in one of the three compounds below. H = -H H = -Me ethyne propyne Synthesis Target 2,4-dimethoxypentane MeOH methanol OMe OMe MeO. OMe C₂H₁₂O₂ Product carbons' origins Draw a box around product C's that came from A1. Draw a dashed box around product C's that came from B1.arrow_forwardDraw the skeletal ("line") structure of the smallest organic molecule that produces potassium 3-hydroxypropanoate when reacted with KOH. Click and drag to start drawing a structure. Sarrow_forward
- draw skeletal structures for the minor products of the reaction.arrow_forward1. Provide missing starting materials, reagents, products. If a product cannot be made, write NP (not possible) in the starting material box. C7H12O Ph HO H 1) 03-78 C 2) Me₂S + Ph .H OH + 2nd stereoisomer OH Ph D + enantiomer cat OsO 4 NMO H2O acetonearrow_forwardPlease note that it is correct and explains it rightly:Indicate the correct option. The proportion of O, C and H in the graphite oxide is:a) Constant, for the quantities of functional groups of acids, phenols, epoxy, etc. its constants.b) Depending on the preparation method, as much oxidant as the graphite is destroyed and it has less oxygen.c) Depends on the structure of the graphic being processed, whether it can be more tridimensional or with larger crystals, or with smaller crystals and with more edges.arrow_forward
- Check the box under each a amino acid. If there are no a amino acids at all, check the "none of them" box under the table. Note for advanced students: don't assume every amino acid shown must be found in nature. ནང་་་ OH HO HO NH2 + NH3 O OIL H-C-CO CH3-CH O C=O COOH COOH + H2N C-H O H2N C H CH3-CH CH2 HO H3N O none of them 口 CH3 CH2 OH Хarrow_forwardWhat is the systematic name of the product P of this chemical reaction? 010 HO-CH2-CH2-C-OH ☐ + NaOH P+ H2Oarrow_forward1. Provide missing starting materials, reagents, products. If a product cannot be made, write NP (not possible) in the starting material box. a) C10H12 Ph OMe AcOHg+ + enantiomer Br C6H10O2 + enantiomerarrow_forward
