Interpretation:
Whether the cyclization and formation of a bicyclic product when (1Z,3Z,5Z)- 1,3,5-cyclononatriene is heated at 100ºC takes place in conrotatory or disrotatory manner is to be identified. Further the stereochemical relationship of the two hydrogens at the ring junction, cis or trans is to be stated.
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 identify:
Whether the cyclization and formation of a bicyclic product when (1Z,3Z,5Z)- 1,3,5-cyclononatriene is heated at 100ºC takes place in conrotatory or disrotatory manner.
To state:
The stereochemical relationship of the two hydrogens at the ring junction, cis or trans.
Trending nowThis is a popular solution!
Chapter 30 Solutions
Organic Chemistry
- Consider the reaction between (1S,3S)‑1‑chloro‑3‑methylcyclopentane and methanethiol in the presence of sodium hydroxide. (a) Draw the organic product and clearly indicate stereochemistry by showing the hydrogen on the chirality centers and using wedge and dash bonds. (b) Then analyze the stereochemistry of the product. racemic chiral achiral (1R, 3S) (1R, 3R) (1S, 3S)arrow_forwardCompound (2E,4Z,6Z,8E)-2,4,6,8-decatetraene has been cyclized to give 7,8-dimethyl- 1,3,5- cyclooctatriene. Predict the manner of ring-closure-conrotatory or disrotatory-for both thermal and photochemical reactions and predict the stereochemistry of the product in each case. Show the outermost molecular orbital cyclizaion.arrow_forwardThere are several isomeric alcohols and ethers of molecular formula C5H12O. Propose a structure for the isomer. Isomer B: δ = 0.92 (t, 7.8 Hz, 3 H), 1.20 (s, 6H), 1.49 (q, 7.8 Hz, 2H), 1.85 (s, 1H) ppmarrow_forward
- (c) Hydrolysis of the haloalkane shown below results in the formation of two alcohols B and C that are stereoisomers of each other. Give the structures of the alcohols B and C and propose a mechanism for their formation ensuring that you explain the stereochemical outcome observed. H3CH2C CH3 H20, heat Br B + Carrow_forwardI have a trans-3-chloro-1-methylcyclopentane. I react it with ethanol with heat. Knowing heat favors elimination, I suspect 3-methyl-cyclopentene as a product. Will I also get the substitution product 3-methoxy-1-methylcyclopentane, a pair of enantiomers and a pair of diastereomers?arrow_forward10:29 0. O ? 86% AIATS For Two Year Medic. A 61 /180 (02:55 hr min Mark for Review When 2-Methylpropene undergoes oxidation in the presence of acidic K2Cr2O7, the products obtained are CH3 – CH + CO2 CH3 — СH — С—ОН-СО, CH, -C =0+CO2 +H2O CH3 CH; – CH2 – CH + CO2 + H20 Clear Response IIIarrow_forward
- Draw curved arrows and identify the thermal and photochemical products of the electrocyclic reaction of (2Z,4Z,6E)-octa-2,4,6-triene. Step 2: An electrocyclic reaction will undergo a concerted electron shift to form a cyclic ring. A new sigma bond will be formed between carbons 2 and 7. The product will be neutral. (2ZAZ,6E)-octa-2,4,6-triene Draw the curved arrows to show the mechanism. Select Draw Rings More Erasearrow_forwardTreatment of the following stereoisomer of 1-bromo-1,2-diphenylpropane with sodium ethoxide in ethanol gives a single stereoisomer of 1,2-diphenylpropene. Predict whether the product has the E configuration or the Z configuration. HC,H, CH3 H3C CH,CH,0 Na* Br C,H;CH=CC,H; CH,CH,OH 1-Bromo-1,2-diphenylpropane 1,2-Diphenylpropenearrow_forwardDHA is a fatty acid derived from sh oil and an abundant fatty acid in vertebrate brains. Hydrogenation of DHA forms docosanoic acid [CH3(CH2)20CO2H] and ozonolysis forms CH3CH2CHO, CH2(CHO)2 (ve equivalents), and HCOCH2CH2CO2H. What is the structure of DHA if all double bonds have the Z conguration?arrow_forward
- 5A Explain which of the following statements are true and which are false. i. N,N'-dicyclohexylurea (DCU) is the dehydrating reagent that converts a carboxylic acid to the corresponding anhydride. ii. The fact that carbonyl compounds have a lower boiling point than alcohols with the same C atoms is because the molecular dipole moment of carbonyl compounds is less than that of alcohols. iii. 3-Methylbut-2-en-2-ol is the only tautomeric structure of 3- methylbutan-2-one.arrow_forwardA tautometric keto (A) – enol(B) equilibrium may be formulated as follows (A) (B) CH3 – COH ß-----------àCH2 – CHOH Given the following bond energies: C – H = 435kJ mol-1 C – C = 368 C==C = 610 C – O = 357 kJmol-1 C==O = 748 kJmol-1 O – H = 462 kJ mol-1 Calculate the enthalpy change in going from Keto form (A) to the enol form (B)arrow_forwardOrganotin compounds play a significant role in diverse industrial applications. They have been used as plastic stabilizers and as pesticides or fungicides.One method used to prepare simple tetraalkylstannanes is the controlled direct reaction of liquid tin(IV) chloride with highly reactive trialkylaluminum compounds, such as liquid triethylaluminum (Al(C2H5)3). 3SnCl4 + 4Al(C2H5)3 3Sn(C2H5)4 + 4AlCl3 In one experiment, 0.230 L of SnCl4 (d = 2.226 g/mL) was treated with 0.396 L of triethylaluminum (Al(C2H5)3); d = 0.835 g/mL). If 0.335 L of tetraethylstannane (d = 1.187 g/mL) were actually isolated in this experiment, what was the percent yield?arrow_forward