Chemistry 242a: Chemical Synthesis Fall 2011 Sarah E. Reisman office: 301B Schlinger lab: 311 Schlinger phone: (626) 395-6044 office hours: M F, 10-11 am or by appointment email: reisman@caltech.edu course website: http://reismangroup.caltech.edu/242a_Website/242a_Home.html Teaching Assistants: John Yeoman Roger Nani Haoxuan Wang Maddi Kieffer Andy Lim Alan Cherney Corey Reeves email: yeomanjo@caltech.edu nanir@caltech.edu hwwang@caltech.edu mkieffer@caltech.edu allim@caltech.edu acherney@caltech.edu creeves@caltech.edu desk: 315 Schlinger Lab 305 Schlinger Lab 305 Schlinger Lab 305 Schlinger Lab 315 Schlinger Lab 305 Schlinger Lab 306 Schlinger Lab phone: x6061 x6061 x6061 x6061 x6061 x6061 x4048 Lectures: 147 Noyes (29 total) M W F 9:00 a.m. September 26– December 2, 2011. No class Friday, November 25, 2011 (Thanksgiving recess) Recitation: Tu 7–9 p.m. Problem Set Tutorial: Th 7–9 p.m. Required Texts: 1. Kürti, L.; Czakó, B. “Strategic Applications of Named Reactions in Organic Synthesis” Optional Texts: (all are excellent reference resources and highly recommended) 1. Warren, S. “Designing Organic Syntheses: A Programmed Introduction to the Synthon Approach” 2. March, J.; Smith, M.B. “Advanced Organic Chemistry, 6th Edition” 3. Corey, E. J.; Cheng, X.-M. “The Logic of Chemical Synthesis” 4. Nicolaou, K. C. “Classics in Total Synthesis” vol.'s 1 (w/Sorensen) and 2 (w/Snyder) 5. Hegedus, L. S. “Transition Metals in the Synthesis of Complex Organic Molecules, 3rd Edition” 6. Greene, T. W.; Wuts, P. G. M. “Protective Groups in Organic Synthesis” 7. Hudlicky, T.; Reed, J.W. “The Way of Synthesis” 8. Carreira, E.M.; Kvaerno, L. “Classics in Stereoselective Synthesis” 9. Corey, E. J.; Kurti, L. “Enantioselective Chemical Synthesis” The above textbooks are available on reserve in Millikan Library, and can be purchased through the Caltech AdoptaText website: https://access.caltech.edu/adoptatext/home Model Sets: HGS molecular model sets are available in the Crellin stockroom from Joe Drew. Additional versions are available at the following website: http://www.maruzen.info/hgs/catalog/index.php?cPath=11 The Stereochemistry 4010/Student set is a cost effective option. Students are strongly encouraged to purchase at least one model set. Other relevant texts and references: 1. Larock, R. C. "Comprehensive Organic Transformations" 2. The Merck Index 3. The Aldrich, Strem, and Acros Catalogs 4. Beilstein/Discovery Gate, Sci-Finder (Chemical Abstracts Service) and Web of Science online. For a complete list of on-line resources, see the Caltech Library link on the next page. 5. Paquette, L. A. "Encyclopedia of Reagents for Organic Synthesis, 8 Volume Set" (now available online through the “e-Eros” link from the Caltech Library homepage). Chemistry Library Web Site: http://library.caltech.edu/collections/chemistry.htm Problem Sets: Problem Sets will be distributed on Fridays and are due by 7:00 p.m. on the following Thursday night; a weekly problem session will be held on Thursday evenings in 147 Noyes beginning at 7:00 pm. Students will be expected to discuss their answers to the problems at the board. This will be the only opportunity to see the solutions to the problem sets. Reading selections from Warren’s “Designing Organic Syntheses” are assigned in the syllabus weekly. You should complete the assigned pages by the specified date in this syllabus. This work should be completed individually. The evening sessions are optional for undergraduates enrolled in 242a, however attendance and participation is strongly encouraged. Extra credit will be awarded to undergraduates for participation. Synthesis Project: Each student will be assigned a molecule for which they must design and propose a total synthesis. A 1-page schematic rough draft your retro-synthetic analysis will be due Friday, October 28th. A two page written proposal will be due on Tuesday, December 6th. Each student will give a 7-minute presentation of his or her synthetic route during either the November 29th (Tuesday) or December 1st (Thursday) evening session. Molecule assignments and further details will be distributed on Friday, September 30th. Name Reactions: There are a number of key reactions in organic chemistry that have become identified by a name (either a person or a specific transformation). Knowledge of these reactions is fundamental to your success in this class. You should learn each of the reactions listed by the date indicated on the name reactions handout at the end of this syllabus. They will appear on exams and problem sets in a timely fashion. Current Literature: The state of chemical synthesis is highly dynamic and changes on a daily basis. In order to keep pace with new developments, part of the requirement of this course will be to stay abreast of new and particularly relevant publications in the primary synthetic literature. Students will be required to read the primary literature, and distill out pertinent developments and report them back to the class. This important exercise will take place during the Thursday problem sessions. Members of the class will be given a playing card, and during the session a deck of cards will be cut and two students with the matching cards will present a synopsis of a relevant communication from a recent issue of J. Am. Chem. Soc., Angew. Chem. Int. Ed., Org. Lett., J. Org. Chem., or Tetrahedron Lett. Be sure to include the primary author, institution affiliation and proper reference in your description. This serves the purpose of not only keeping the class current, but also will help students to launch their own database of relevant chemical literature. If your teaching schedule permits, you should also plan to attend the OCS seminars. The seminars are typically held on Wednesday afternoons at 4 pm. For specific dates, see: http://today.caltech.edu/eas/listing.adp?template=cce&sponsor_id=361&sponsor_id=142&range=this_week Exams: There will be two midterm exams and a comprehensive final. The exams will be take-home and in some cases outside resources may be consulted (e.g., class notes). Please follow the instructions precisely as they are given on each exam. Exam Due Dates: Monday, October 24, 2011 - 9 AM Monday, November 21, 2011 - 9 AM Final Exam Due Date: Friday, December 8, 2011 – 5 PM Course Grade: The course grade will be based on midterm exams (40%), problem sets and discussion (10%), synthesis proposal (15%), and the final exam (35%). Extra credit will be awarded to undergraduates for participation in problem discussions (up to 10%). Course Syllabus: Chem 242a class date topic course work due 1M 2W 3F 9/26 9/28 10/1 introduction and retrosynthetic analysis conformational analysis synthesis Friday PS #1 due (9/29) molecule assignments distributed 4M 5W 6F 10/3 10/5 10/7 conformational analysis oxidation synthesis Friday PS #2 due (10/6), Warren p. 1-75 7M 8W 9F 10/10 10/12 10/14 oxidation stereoselective oxidation stereoselective oxidation PS #3 due (10/13), Warren p. 77-130 10M 11W 12F 10/17 10/19 10/21 synthesis Monday stereoselective oxidation hydrogenation PS #4 due (10/20), Warren p.131-172 midterm #1 out 13M 14W* 15F 10/24 10/26 10/28 stereoselective hydrogenation carbonyl reduction synthesis Friday midterm #1 due 9 a.m. *lecture will start at 8:45 a.m. synthesis prop retro due 5 p.m. 16Tu* 17W 18F 11/1* 11/2 11/4 carbonyl addition enolates enolate alkylation *lecture will be held from 7-8 pm PS #5 due (11/3), Warren p. 173-200 19M 20W 21F 11/7 11/9 11/11 aldol aldol synthesis Friday 22M 23W 24F 11/14 11/16 11/18 asymmetric aldol stereoselective allylation synthesis Friday 25M 26W 11/21 11/23 stereoselective allylation synthesis Wednesday midterm #2 due 9 a.m. 27M 28W 29F 11/28 11/30 12/2 12/5 12/6 12/8 metal carbenoids transition metal cat. C–C bond formation synthesis Friday Ch 242a Symposia on 11/29 and 12/1 PS #6 due (11/10), Warren p. 201-254 PS #7 due (11/17) midterm #2 out final exam out synthesis props due 5 p.m. final exam due 5 p.m. Name Reactions Below are some name reactions that are of importance in synthetic organic chemistry. You are expected to know the overall transformation and a reasonable mechanism for each reaction by the date indicated. Good references: L. Kürti, B. Czakó, “Strategic Applications of Named Reactions in Organic Synthesis” J. March, M.B. Smith, "Advanced Organic Chemistry, 6th Edition" J. J. Li, "Name Reactions" Websites: http://www.organic-chemistry.org/namedreactions/ http://www.monomerchem.com/display4.html 10/1 aldol reaction (technically not named) Mannich reaction Diels-Alder reaction Alder ene reaction Michael addition Robinson annulation Dieckmann condensation Grignard reaction Swern oxidation Jones oxidation 10/8 Fischer indole synthesis Pummerer rearrangment Beckmann rearrangement Curtius rearrangement Hofmann rearrangement Bamford-Stevens reaction Ritter reaction 10/15 Claisen rearrangement Cope rearrangement Ireland-Claisen rearrangement Oxy-Cope rearrangement Overman rearrangement Aza-Cope Mannich reaction Mislow-Evans rearrangement Prins-Pinacol rearrangement Baeyer-Villiger oxidation 10/22 Baeyer-Villiger oxidation Rubottom oxidation Oppenauer oxidation Meerwein-Ponndorf-Verley reduction Wacker oxidation Tamao-Fleming oxidation Tischenko reduction Luche reduction Wittig reaction Horner-Wadsworth-Emmons reaction 10/29 Brook rearrangement Corey-House reaction Julia-Lythgoe olefination Wharton alkene synthesis Peterson olefination Chugaev Reaction Saegusa-Ito oxidation 11/6 Arndt-Eistert homologation Wolff rearrangement Neber Rearrangement Henry reaction Simmons-Smith reaction Wolff-Kischner Reduction 11/13 Knoevenagel reaction Mukaiyama Aldol reaction Sakurai reaction Reformatsky reaction Favorskii rearrangement 11/20 Grubbs olefin metathesis Stille reaction Suzuki reaction Heck reaction Negishi reaction Sonagashira reaction Tsuji-Trost allylation 11/27 Krapcho Decarboxylation Finkelstein reaction Hunsdiecker reaction Mitsunobu reaction Strecker reaction Barton-McCombie Deoxygenation