Hey, remember how much fun we had with the alpha carbon position? Those were some good times, huh? Well, let's run it back. In this section, we're going to be working with the alpha carbon again, but we'll be performing alpha deprotonation on esters, 1,3-dicarbonyls, and diesters. With this new class of enolate nucleophiles, we'll see the unique chemistry we can do, such as the Claisen Condensation, Decarboxylation, Malonic Ester Synthesis, and so much more.
https://joechem.io/videos/140 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we get up close and personal with the Claisen Condensation. We'll step through how the Claisen Condensation proceeds mechanistically, what requirement MUST be there for a Claisen Condensation to go to completion, and a few examples of Claisens, both mixed and non-mixed.
https://joechem.io/videos/141 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we take what we know about the Claisen Condensation and run it in reverse. That's right--in this video, we tackle the Retro Claisen Condensation. If you're a bit shaky on the Claisen Condensation itself, revisit the video where we discuss that. Otherwise, let's hit it.
https://joechem.io/videos/142 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link) In this video, we consider the Diekmann Condensation. Lucky for us, this is just a Claisen Condensation that forms a cyclic product. So as long as we have a good handle on the Claisen Condensation, the Diekmann will be a breeze.
https://joechem.io/videos/143 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we tackle three synthesis problems where we'll focus on retrosynthesis. This video is meant to be an exercise in looking at a synthetic target, recognizing it was produced by either a Claisen/Diekmann Condensation, and reverse engineering what enolate and substrate reacted together.
https://joechem.io/videos/145 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we keep hanging out with our good friend the ester enolate, this time taking the forms of 1,3 diesters, dicarbonyls, and ketoesters. Although we've seen the inner workings of the Claisen Condensation, this video is meant to remind us that we can still do plain ole' Sn2 with this class of nucleophiles. Luckily, we're Sn2 pros--so nothing actually new here.
https://joechem.io/videos/146 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we tackle decarboxylation. This commonly pops up in complete the reaction questions, and its TRULY not that bad, which means easy points on exams for us.
https://joechem.io/videos/147 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we cover the Malonic Ester Synthesis from front to back. While it's annoyingly long, mechanistically speaking, it's not that bad. It's nothing new, chemistry wise--it's just a bunch of concepts you have previously learned in Ochem II strung together.
https://joechem.io/videos/148 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we throw it back to an old friend--the Michael Addition. We'll see the various ways we can use these new 1,3-dicarbonyls to perform Michael Additions as well as, that's right, Robinson Annulation. But come along for the ride: It's not that bad, I promise.