Electrophilic Addition Of Hx To An Alkyne H C 9 1 Alkynes Worksheet H H Br Step 1 Br H X H C 1 (65.89 KiB) Viewed 12 times
Electrophilic Addition Of Hx To An Alkyne H C 9 1 Alkynes Worksheet H H Br Step 1 Br H X H C 2 (44.87 KiB) Viewed 12 times
Electrophilic Addition of HX to an Alkyne H₂C- . . . . . . . . . ● . . 9.1 Alkynes Worksheet H+ H-Br Step 1 Br. H X H₂C vinyl bromide HBr Step 2 Br - Be H -H CH₂ H geminal dibromide Br Hal H What product is formed after addition of one equivalent of HBr (Step 1)?...... In the product formed after step 1, the Br is bonded to one of the carbons of the double bond (circle one true/ false. to more substituted Complete the following sentence. The name vinyl bromide means the Br is Attached What product is formed after addition of the second equivalent of HBr (Step 2)? In the product formed after Step 2, the two Br groups are attached to the (circle one ame different carbon. The term germinal dibromide means the Br groups are: How many n-bonds does an alkyne have? 1 In the example in the model, how many bonds have reacted in step 1? How many n bonds have reacted in step 2? How many n bonds have reacted in total? Is the alkyne acting as a nucleophile or an electrophile? Explain. Consider the addition of HBr to an alkyne as shown in the model: Draw the two possible vinyl cations (using curved arrows to show formation) after the addition of HⓇ in step 1 H Of the two vinyl cations drawn above, which would be the most favorable? Explain why. Check that the most favorable vinyl cation leads to the vinyl bromide shown in the model. Does this follow. Markovnikov's rule? (Circle one) yes / no. Explain. Starting with the vinyl bromide, draw (using curved arrows) the two possible cations formed after the addi of HⓇ in step 2.
Hydration of Alkynes (Addition of H₂O) H₂CH. 1₂01 ● . . . . In the reaction shown in the above model: The addition of water to an alkyne occurs to give a vinyl alcohol. What is another name for a vinyl alcohol? Explain how this other name is derived. H- tautomercre H₂C vinyl alcohol (enol) HCH₂CH₂ The vinyl alcohol rapidly tautomerizes to form a ketone. Based on the arrows depicting this step, which compound would you expect to be the most stable? H₂C Describe what happens in general terms in the tautomerization step. Below is the acid catalyzed hydration of 1-butyne. H HⓇ ketone In the hydration of propyne shown above, does the addition reaction occur according to Markovnikov's rule? (Circle one) yes/no. Is this the same as hydration of alkenes? (Circle one) yes / no. H₂O H The product shown above is the (circle one) Markovnikov / anti-Markovnikov product. Using your knowledge of the acid catalyzed hydration of an alkene, devise a mechanism for the above reac using curved arrows to show electron movement.
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