CHEM243

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pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

pdf Right-click and select "save target as" if downloading manually.

Review from email questions, class questions and the questions most wrongly answered from test 1.mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We played "Wheel of Orgo" again today, with the modification that I only counted a point for reactions only if they were correct. Again 3 points for completing the synthesis. We did 2 relatively simple syntheses then started one difficult one (vanillin). We didn't get the chance to finish that one so we'll resume next time. Again Sujeet ended up with the most points at the end. I would encourage you to think of ways of finishing this synthesis with the reactions we have learned. It is a good way of consolidating the material in this class. You don't need to participate, you can pass your turn and you can join the game in progress. If you are taking the class online and would like to participate in a future Wheel of Orgo session email me so that I can plan future sessions.mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We covered most of problem 11 about enol reactions. We will resume Wheel of Orgo on Friday. mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

The compound hydroxylamine is remarkably close in structure to ammonia, and differs only in containing an additional hydroxyl, thereby giving it basic properties. Normally a crystalline compound at room temperature, this base is also known to play significant roles as a reducing agent as well as in imine formation.Imines are highly reactive nitrogen double-bond containing compounds that are formed through an addition reaction with a carbonyl group in acidic conditions (aldehyde/ketone): Despite their rather explosive nature, hydroxylamines are useful compounds in themselves or in their other derived forms.For more information on hydroxylamines, click on this link.1). Hydroxyammonium NitrateBeing the salt of hydroxylamine and nitric acid (via an acid-base reaction), this corrosive and toxic substance is held in high regard by rocket scientists, as this compound is considered to be a potential rocket propellant. The following shows the synthetic mechanism of creating this compound:Click on this link for more information on the properties of the energetic compound hydroxyammonium nitrate and its significant use as a rocket propellant.Click on this link directing to a Chem 243 lecture describing the various reactions of aldehydes and ketones (including imine formation).2). Separation of Aldehydes and Ketones using Oxime DerivativesIn the case of hydroxylamines, the resulting imine products that are formed from their interaction with a carbonyl in acidic conditions results in the formation of a special subset of imines known as oximes (from aldehyde – aldoxime/from ketone – ketoxime). Oximes are normally colorless crystalline compounds. In fact, it is this property of these compounds that allow for their usage in determining the identity of the respective aldehyde/ketone that the hydroxylamine originally reacted with. In the following example, the use of the hydroxylamine derivative para-nitrobenzyl hydroxylamine is reacted with the respective carbonyl compound. As a result, the new compound is easily able to be detected and identified through separation techniques such as High Performance liquid Chromatography (HPLC), as the nitro groups increase molar absorptivity and increased sensitivity. In addition, alkylated oxime groups are more easily seperated by the technique HPLC than standard ones.As the peer article referred to didn’t provide a mechanism as to how the p-nitrobenzyl hydroxylamine was synthesized, I have provided a sample mechanism that leads to its production:This link leads to the respective peer review article referred to in obtaining this information.Click on one of the following three links that direct to Chem 243 lectures for information on:A) Electrophillic Aromatic Substituion (use of Friedel-Crafts Alkylation in order to add a methyl group to a benzene ring).B) Ortho/Para Vs. Meta Directing Groups (ability of methyl group on benzene ring to direct the respective nitro group being added on through a nitration reaction to a para position).C) Side Chain Reactions of Aromatic Compounds and introduction to Aldehyde and Ketone properties (substitution of methyl's hydrogen on the benzyl position with bromine through free radical halogenation).3. Synthesis of CaprolactamCaprolactam is one the many monomeric subunits used in the overall synthesis of the material Nylon-6. Once an imine synthetic reaction is performed on a cyclohexanone with a hydroxylamine, the resulting product can be converted into caprolactam through a specific reaction known as the Beckmann Rearrangement. The Beckmann Rearrangement is an acid catalyzed reaction that allows for the conversion of an imine into an amide, as seen below:For more information on the synthetic properties of the formed caprolactam, please click on this link.Compound InfoHydroxylamine: PubChem 789 hydroxylamine Oxammonium Oxyammonia Nitroxide NH2OHChemACXnet to purchase ACX number X1008257-2 CAS number 7803-49-8

There were no questions for the exam so we did one last Wheel of Orgo to practice reactions from the whole course. There were 3 enol reaction patterns to identify in the first 2 syntheses. Then we synthesized a cat from glycine.mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We went over some common mistakes made in test 2, mainly on enol chemistry.mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

Here are directions for completing the extra credit for this class. In the screencast I show how to:1) Download ChemSketch (only for Drexel students)2) Use wikipedia and Google scholar to find an article with a relevant synthetic step.3) Draw out the single step reaction with ChemSketch.4) Use Paint to convert the ChemSketch work into a bitmap file.5) Create a Flickr account to upload the bitmap file and create a tag. (Everyone in my classes use at least the "orgo" tag in Flickr.)6) Find the url referencing the picture in Flickr using properties and insert into a blog post. (I also go through creating a Blogger account)7) Give a brief description of the reaction and link to at least one peer-reviewed article.Notice that all the services are completely free. A freeware version of Chemsketch is available here. I don't know how it compares to the Drexel version.The example I used was the last step in the synthesis of ibuprofen - the hydrolysis of a nitrile. This is what it looks like.Remember the last day to have the extra credit work done is Friday June 3, 2005 at midnight.mp3 podcast Right-click and select "save target as" if downloading manually.There is no pdf for this lecture.streaming screencast Flash

I gave the solutions to the extra enol problems I posted on Monday and answered questions about the test.mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We finished problem 12 on enol chemistry and completed the list of the patterns to look for in these syntheses. At the end of class I put up a few more problems of varying difficulty then assisted students in small groups. I'll post the solution to these on Wednesday. The test will be available Wednesday afternoon, a little earlier because Sunday and Monday Korman is closed. I will answer questions on Wednesday concerning the test then if there is any time left we'll do another Wheel of Orgo. Online students make sure to email me your questions. mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We did some enol chemistry synthesis problems. If you are having trouble with this section make sure to see me after class or schedule an appointment so I can see how you are approaching the problems. mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

Another round of Wheel of Orgo. This time Sri won. All of the syntheses were designed to practice enol reactions. mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We finished problem 11 (j-p) on enol reactions. It was a mix of Claisen condensations, malonate ester and acetoacetate ester syntheses. The last problem was an example of a Robinson annulation. mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash

We played another Wheel of Orgo with the target products vanillin, TNT and DEET.Mihir won this one.I reduced the resolution of the Flash presentation to 800x600 so you don't need to scroll if you are running you desktop at 1024x768. For all prior lectures, you can avoid scrolling by increasing the resolution of your screen. mp3 podcast Right-click and select "save target as" if downloading manually.pdf Right-click and select "save target as" if downloading manually.streaming screencast Flash