synthesis

= The purpose of this exercise is to take the reactions that you are learning to the next level, and bring them together to build creative synthetic strategies. An equally important goal is to develop the skills of creative cooperation in this endeavor. Organic chemists seldom work alone, but rather consult with each other to determine what weaknesses a plan may have before setting out on a multi step synthesis, and to determine alternative synthetic strategies in case a planned step does not provide the expected product. There are a few rules that we need to follow in order to maintain a high standard and to give each class member the best opportunity to make contributions. These are: = = 1) A maximum of 3 people can sign up for any one molecule = = 2) Between now and April 10, you may sign up for only one molecule. This gives all class members a chance to take part in this project. If you have ideas about another molecule, you may message the people that are working on that molecule to share your ideas, but please refrain from posting synthetic schemes on another molecule to give them a chance to figure it out. = = 3) After April 10, you can sign up for any molecule that is still available. Any work that you do counts for extra credit up to a maximum of 100 points. = = 4) If you do not post anything on the prolem within 1 week of signing up for it, your name may be taken off of the list, and another person's put up. Post early, and post often. Your work on this wiki is not a finished product, but a work in progress until the end of the term = = 5) A complete project that recieves full credit should consist of the following: = = A) at least one retrosynthetic analysis (disconnection) (see Wade, pages 372 through 374) = = B) a reaction scheme showing each of the synthetic steps with starting = = materials, products, reagents and conditions = = C) a paragraph or so describing the logic of a synthetic strategy and why it would = = be the most likely to give the desired product. = = D) References to any sources that were used. These should include the journal title, = = volume, issue, year and page number, the book title, auther, publisher, = = and page number, or the website title, URL and author. ** It is not sufficient to just **= =** cut and paste a reaction sequence from a journal without really understanding **= =** what is going on in the synthesis. **= = 6) All reactions that are proposed should be accompanied by a page reference to a book journal article or web page (with web pages pay attention to papers referenced in that page. If there are none, be suspicious of the information there.) The reference should contain sufficient information for a reader to find the exact page of that book or journal article where that reaction can be found. = = 7) At least one reference should be to a source other than Wade. = = 8) Carbon limits on starting materials do not apply to reagents that do not contribute carbon atoms to the target molecule, for example, triphenyl phosphene or Sia-Borane can be used even if the carbon limit is two or six. These are all the rules. My suggestion is to post frequently and create a lively dialogue on the synthetic strategy. Design of an organic synthesis, like any other creative endeavor, does not happen in a single step, but is rather a process of thinking, writing, rethinking, and rewriting. You will be graded, not on whether you come up with the perfect synthesis in one try, but rather on the quantity and quality of your contributions. You can always respond and re-work your strategy according to the suggestions of others. I will comment on the proposed synthesese as much as possible, to give you a chance to work out the bugs. For this reason it is important to post early and often, not to wait until the last minute Remember that there is more than one correct synthesis, just as there are many incorrect ones. In evaluating alternatives, take into account that the best synthesis = = 1) minimizes the number of steps, = = 2) has reactions that yield predominantly the desired product, with a minimum of side products, = = 3) subsequent reactions do not affect the desired functional groups placed by previous reactions (i.e. the most labile functional groups are placed last). When you see something that you would like to work on, Click "edit" in upper right. Put your name down, and click "Save". Then click the blue link in the bottom of that text section. This will take you to the page of that molecule. You can also click the link from the home page. You make changes in the molecule page the same way. To insert pictures you first need to upload them from your computer. Do this by clicking on the picture above, beside the TV set. Then click on the upload tab. It is best to get together as a group and divide the work. Make a note of who did what on the molecule page. = = Good luck :-) = =**Great website that allows you to find reactions by specifying the product and the reactant:** WebReactions = =Another good source of reactions is this website [|organic synthesis website] **Chemsketch download** here is the hyperlink for[| chemsketch]=

pentacosadiynoic acid == Sign up 1) Quynh Nguyen 2) 3) Ashley Zitnyar

Monomers based on pentacosa-10,12-diynoic acid can be polymerized to make a highly conjugated poly-alkene called 'polydiacetlylene'. This polymer has some interesting properties. It is colored and fluorescent, and the absorption and emission spectra can be changed if the polymer chain is physically deformed. When these polymers are conjugated to functional groups that specifically bind certain molecules or ions, it can be a sensor for thos molecules or ions. NASA has also experimented with growing uniform crystals of polydiacetylene to serve as entirely photonic logic chips. Devise a synthesis of this compound from any starting material of 12 carbons or less that is available in the sigma aldrich catalog. []

Here is an interesting review on polydiacetylenes.

[|carpick_PDAreview_jpcm.pdf]

tremorine

Signup 1) Sean Croteau 2) Rich Mauro 3) Padideh Rezabakhshpour Here is some shaky chemistry. Tremorine is a drug given to laboratory animals to induce the sympthoms of parkinsonism for research on that disease. Make this compound from starting materials containing 4 carbons or fewer. that are available from the [|Sigma Aldrich] catalog.

diyne diol

Signup 1)Julianne Hancock 2) Tim Maynard 3) Jimmy Metellus

This synthesis is a good exercise in alkyne chemistry. Make it from any compound containing 2 carbons or less.

meparfynol

Signup 1)Drashti Kalariya 2)Madhuri Patel 3)Jonas Presendieu Relax! Meparfynol is a seditive and hypnotic. Make this molecule from any starting materials that contain 2 carbons or less. But save it until after finals! alkene

Signup 1) Ana Baird 2)Pierre latortue

3) Moise Civil This molecule is an exercise in alkene chemistry that I made up . Devise a synthesis from any compound containing 4 carbons or less.

octatriene



Signup 1)Jimmy Metellus (extra credit) 2)Padideh Rezabakhshpour (extra credit) 3) Here is more practice making alkenes. Make this compound from any starting materials having 2 carbons or less. Do you remember a reaction that forms carbon-carbon double bonds directly?

linolenic acid



Signup 1) Jesson Bateman 2) Rich Mauro 3) Chris Markham Linolenic acid is one of the famous omega fatty acids that have been found to have beneficial health effects, such as reducing triglycerides and lowering blood pressure. Make this compound from any compound containing 8 carbons or less, that is readily available from Sigma-Aldrich  []

kinoprene



Signup 1)Natalie Gill 2)AliciA MoorE 3)Tavisha Graham Kinoprene is an insect hormone. Derivatives of this type of compound have the potential of being highly selective, and non toxic (to us and non target animals) insectisides. Research in this area may bring about a new "green revolution", Make this molecule from any starting materials that are readily available from the Sigma Aldrich catalog []

cyclopropyl1

Signup 1) Jesson Bateman (Extra Credit) 2) Robert Duong 3) Jillian Long This compound and the next one are exercises in the synthesis of cyclopropyl rings. Make this one from any starting materials having 3 carbons or less.

cyclopropyl2



Signup 1) Ben Kassa 2) Sean Croteau (extra credit) 3) Make a racemic mixture of just these stereoisomers (no trans) from any starting materials having 3 carbons or less.

pyrethrin

Signup 1)Sean Pitcher 2) Jessica Rodriguez 3) Here is the more interesting piece of another natural insecticide, pyrethrin. This compound is produced by the chrysanthemum plant. Variations of this type of molecule are used in many commercially available insecticide formulae, because they have low toxicity to mammals and other higher animals, and they are biodegradable. Make a racemic mixture of this pair of enantiomers from any compounds containing 3 carbons or less.

Alternative project If you know of a different molecule or any subject in Organic Chemistry that you would like to study, You may do so, with instructor permission. Post the results of your study (aprox. 3 page paper, or synthesis, as described in the introduction) to the page called "Alternative Project" The title of this section is also a hyperlink to the page. Write your name and a brief description of what you would like to do below.