Give the expected major product for each reaction, including s...

Question

Give the expected major product for each reaction, including stereochemistry where applicable.

(a) but-1-ene + H₂/Pt

(b) cis-but-2-ene + H₂/Ni

Accepted Answer

welcome back everyone. In today's video, We are going to look at this problem which states for each of the following reactions, determine the major products include stereo chemistry. In your answer, Starting with the first part, we have a reaction between antoine in and hydrogen over platinum catalyst. Now we are going to drop antoine in. So we are starting with a five member chain and we noticed that at position number one we have a double bond. So we are going to add a double bond to our structure that spent one in. And the conditions in this reaction are hydrogen over a platinum catalyst. Because the region does hydrogen gas over a platinum catalyst, we may immediately recognize this as a hydrogenation reaction. Recall that in the hydrogenation reaction we are adding two hydrogen atoms across the double bond. In sent arrangements, we are going to add these to hide jen's insane arrangement. So we draw our structure. First of all, we understand that we will get an owl came because we are reducing a double bond. That double bond at this position was specifically become a single bond since there's an addition of two hydrogen atoms to each carbon atom within that double bond. Therefore, we are drawing our first product. We will not have any double bond president anymore. And now we have to think about the sin arrangement of these high genes. In particular if we draw these two hydrogen atoms and an arrangement meaning on the pointing on the same side of the plane. Supposing that they both are added on wedges. We also noticed that initially we had two hydrogen atoms here. So one of the hydrogen atoms will be pointing away from the viewer and similarly here, initially we had one hydrogen atom, so we will have another hydrogen atom pointing away. Now we are showing stereo chemistry here, but let's think if that is really relevant, of course there is another hydrogen here on the solid line. And the thing is that because none of these two are Cairo carbon atoms notice that the first carbon atom has three hydrogen atoms, so there are no for different substitutions, meaning it's not Cairo and similarly the second carbon is not carol as well. It's just sufficient to understand that there are two equivalent hygiene groups as a result because none of these carbons are Cairo. We may simply to our structure as a five member chain. This is simply insane. That's that we have our product for the first part of the problem and now we are ready to like the second part. If we draw the structure for the second part notice that we have a reaction between between cis penso in and hydrogen over nickel. So we are going to draw six pence to in, we will start with a double bond because we are dealing with a cis is more Sophie draw the double bond. The double bond starts at position two. Just as the name suggests, we will have an additional carbon atom over here. So we have three toes. So, and because it says, we want to make sure that the remaining two carbon atoms are pointing in the same direction as this initial metal group. Because cece implies that the alcohol substitutes are on the same side of the double bond. So we are going to draw C three double bond. Now we have a total of three carbon atoms. We need 12 more. This is cece Bantu in notice that we may also check that carbon atoms at position two. We have a double bond. And it's in this arrangement because the two alcohol groups are pointing on the same side of the double bond. The reaction conditions for this reaction are hydrogen over nickel and notice that this is another hydrogenation reaction because we're using hydrogen over a transition metal catalyst. So, this is another edition of hydrogen. We may also state that this is hydrogenation and because we have a double bond, we are essentially reducing it and we will be producing a single bond out of it, forming an al caine, two hydrogen atoms will be added in syn addition. In other words, the two hydrogen atoms will be added on the same side of the plane and we are ready to draw our product. Now, if we start by drawing it in the same perspective, the two hydrogen atoms here will be added in sin arrangements. So let's suppose they're both added on wedges. And notice that initially there were still two hydrogen atoms along this double bond. So the other two hydrogen atoms will be on dashes. Now this stereo comes through here. Important. Actually, no, because based on the same reasons as we discussed previously, these two carbon atoms are not Cairo notice that there are two exactly same hydrogen is bonded to each of these two carbon atoms and therefore none of them is Cairo. So we're not worried about stereo chemistry. It's just sufficient to notice that this is an L. Kane because we have a saturated chain, five carbon atoms. So we may just draw it just another Pentium molecule. Justice before our product for this one is also been saying we may simply draw it with no stereo chemistry included because it's irrelevant since there are no Cairo carbon atoms. Another Benzene molecule is formed for reaction number two. So this is our answer for the second reaction. In other words, we may conclude that both of these reactions form contain molecules and the correct answer for this multiple choice question is the However, if you feel that you still have any questions don't have states, leave them down below. Thank you for watching this video

Give the expected major product for each reaction, including stereochemistry where applicable.
(a) but-1-ene + H₂/Pt
(b) cis-but-2-ene + H₂/Ni

Key Concepts

Hydrogenation

Stereochemistry

Catalytic Hydrogenation Conditions

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