Why are the halide ions the only nucleophiles that work well in acidic conditions? trans-1-bromo-2-methylcyclohexane reacts...
(a) When cis-1-bromo-2-methylcyclohexane undergoes an E2 reaction, two products (cycloalkenes) are formed. What are these two cycloalkenes, and which would you expect to be the major product? Write conformational structures showing how each is formed. (b) When trans-1-bromo-2-methylcyclohexane reacts in an E2 reaction, only one cyclo- alkene is formed. What is this product? Write conformational structures showing why it is the only product.
7. Predict the SN2 product of this reaction: NaOH CHOH 8. 1-bromo-2-methylcyclohexane reacts via an SN1 mechanism to produce 2 products. Draw the carbocation intermediate that led to each individual product. Qarakia
11/8/19 The cis- and trans-isomers of 1-bromo-2-methylcyclohexane are shown below. One of these isomers undergoes E2 elimination 50 time faster than the other. Illustrate the E2 mechanism using the chair conformers to explain why one isomer is much faster and give the major product of each reaction. 1-BUOK 1-BOK Illustrate the Sw2 mechanism for the reaction below and show what has happened to the stereochemistry of the compound. NaCN acetone
Organic Worksheet How can you explain that trams-1-bromo-2-methylcyclohexane yields the non-Zaitsev elimination product 3-methylcylcohexene on treatment with base? 1-chloro-1,2-diphenylethane can undergo E2 elimination to give either cis or trans- 1,2,diphenylethylene. Draw Newman projections of the reactive conformations leading to both possible products, and suggest a reason why the trans alkene is the major product.
2. (10 points) Explain why the following deuterated 1-bromo-2-methylcyclohexane undergoes dehydrohalogenation by the E2 mechanism to give only the indicated product. н н wCH3 Осн, CH3 wCHs wCH Br H H D H not observed observed
8. Explain why the following deuterated 1-bromo-2-methylcyclohexane undergoes dehydrohalogenation by the E2 mechanism to give only the indicated product. Two other alkenes are not observed CH3 (CH, Br OCH, -CH Сн, H DH DH not observed observed
4. Why does the reaction of trans-1-bromo-2-methylcyclohexane yield the non-Zaitsev elimination product 3-methylcyclohexene on treatment with a base? Draw structures in chair conformations to support your explanation. сн, сн, КОН Br
6. Draw both chair conformations of trans-1-bromo-2-methylcyclohexane. Circle the most stable conformation.
4. The reaction between cis-1-bromo-2-methylcyclohexane and ethoxide (a very strong base) results in an E2 reaction. (refer to Mechanism 9.8 in your textbook) a. Show the transition state for this reaction. CHE + CH, CH, CH, OH b. Show the formation of the product(s) from the transition state. c. Use the rule from part 3d, to determine the major and minor alkene products.
Draw the most stable conformation for; a. trans-1-chloro-3-methylcyclohexane b. cis-1-ethyl-2-isopropylcyclohexane c. trans-1-bromo-4-ethylcyclohexane d. cis-2-bromo-1-methylcycclohexane Sppecifically, show the ring flipping and calculate the strain using the table given in the power point slides.