Unformatted text preview:

I. (46 points)piperacillin(a) Circle all the tetrahedral (chiral) stereocenters in both piperacillin and tazobactam and give the appropriate stereolabel.hybridization electronic geometry observable geometryatom Oatom N122Name _______________________Page 1sp2sp2trigonal planartrigonal planarbentbentall three answers must be right for the row = 2 no partialatom N22sp2trigonal planar trigonal planaratom C2sp3tetrahedral tetrahedral"Pip tazo" is a nickname given to a popular combination of antibiotics prescribed for a variety of infections.For each of the atoms indicated with an arrow, provide the atom's most reasonable hybridization as well as its electronic geometry (VSEPR) and observable geometry (write none if it is not observable).18CON2N1Be sure to include all information on connectivity and stereochemistry in your drawings and your naming.H3CC(S)(S)CCBrA.B.C.2 pts each: site with label and two rings with 6s -2 pts each for circling non-sites and for highlighting other ringsNNOOONON(R)(R)N(R)(R)(S)(S)SOOO(R)(R)HHHHtazobactamN(R)(R)(S)(S)(S)(S)SOONNNOOOH(b) Identify any/all aromatic groups by using an arrow to point to the ring system; write the total number of delocalized electrons in the system next to the arrow.662 points each for aromatic rings and 6 written next to it-2 per ring for circling other ringsNSOONNNOOOHtazobactamBrHNaBr(c) Provide an accurate and complete three-dimensional orbital picture for this organic product (considering all valid resonance contributors when you assess hybridization for each atom). You should use lines, dashes, wedges, and p orbitals (lone or overlapping) to show the direction of all electrons (or empty orbitals) in your drawing; you may just write -CH3 for the methyl group. All bond angles should reflect the appropriate geometry and hybridization chosen for your drawing.CBrCH3CHC2 points per atom - geometry must be correct bond angles must be accurateone Br is sp2, one is sp3 must have p orbital consistent with planeH3CC(R)(R)CCBrHClNaCl(S)-1,3-dibromobut-1-yne(a) Provide the structure of the C4H4BrCl starting material(b) Provide the complete name for the organic product shown, with stereochemical labels if needed.Br4610- 3 points each errorName _______________________Page 2II. (33 points)A.NOHONIn January of 2016, Meldonium, an off-market anti-ischemia drug, was added to the list of pharmaceuticals banned for athletes. It recently made the news when Maria Sharapova (WTA) admitted that she has been using the drug for ten years.C1C2HH NHHB.OO(a) Draw a Newman projection of the C1-C2 bond in a conformation in which some intramolecular interaction occurs; view with the C1 in front, and Indicate at least one specific interaction that could inhibit bond rotation by circling the specific atoms involved.(c) From the set of bases given in the box below, circle those bases that can deprotonate the most acidic proton meldonium favorably (Keq > 104).NOOOHOH3CNHNH3CCH3CH3KO ONaNaconnectivity AND gauche t for 3 pointsonly NH (not N+) and COOH can be Hbond donor or acceptor but some interaction must be clearly shown for 36.515HmeldoniumNHdonorHdonoracceptoracceptor(b) Ischemia is the reduction of blood flow in certain areas of the body, often noticed by a bluish tinge to tissue. Given that the only acidic proton in meldonium has a pKa of 4, draw the form(s) of meldonium that would predominate in the bloodstream at pH 7.2.NOONH5.210.6NHH4.6 17635HHHHElectrophilic aromatic substitution reactions are very important in the synthesis of many pharmaceuticals, including the very famous ibuprofen. Follow the first reaction in the synthesis of this common over-the-counter drug. You may use HB+ and :B as needed.OOClDraw the electrophilic partner hereCOCO2 ptsOH:BOAlClClClOClOClAlClClClCOCO(a) Show the formation of the electrophilic partner; be sure to show the best possible structure and all products.10(b) Show the complete EAS reaction, using the electrophile you generated in part B(a).9optional pink arrow - right to best resonanceClAlClClCl2 pts 3 pts per mechanistic step (either contributor) and 3 pts intermediateElectrophilic partner and all other productsAlCl3all three and only those - no partial credit2 pts each step, each intermediate/productName _______________________Page 3III. (44 points)Each of the following transformations demonstrates some form of selectivity yielding a single major organic product. Provide the other information requested.HBrB.Cl2FeCl3NaCN(S)(S)CNBrCl(R)(R)BrClClClHHBrHHNH2OSOOCH3CH3OMsNH2HHHCH3A.(ii) Draw a Newman projection showing the conformational alignment favored for the formation of the product. The C with the leaving group should be in front.(iii) Draw the complete chair conformation for Molecule 1 that shows the conformational alignment favored for the formation of the elimination product. Be sure to show axial and equatorial positions for all substituted ring atoms. Then provide the curved arrow mechanism for this reaction.OO(ii) Draw the productHONH2CH3NH2OHCH3NCl SOOCH3(i) Draw the starting material(iii) Show the chair conformation of Molecule 1 favored to undergo an E2 reaction and provide the mechanism4475 pts for chair and specific conformationthen last 2 pts for correct mechanism (all three arrows) with the correct aligned H(i) Draw the product4first 3 must be correct connectivity and stereothen 2 for conformation5(a)(b)(ii) Draw the product4(ii) Draw the product4(c)a diastereomeric pairan enantiomeric paironly chiral molecules1 unique moleculeXX3 or more stereoisomeric moleculesThis connectivity representsonly achiral moleculesa diastereomeric pairan enantiomeric paironly chiral molecules1 unique moleculeXX3 or more stereoisomeric moleculesThis connectivity representsonly achiral moleculesa diastereomeric pairan enantiomeric paironly chiral molecules1 unique moleculeX3 or more stereoisomeric moleculesThis connectivity representsonly achiral moleculesXFor each of the following connectivity drawings check all the descriptions that apply.(a) (b)(c)444OMolecule 1all or nothing all or nothingall or nothingName _______________________Page 4IV. (40 points)A.optically inactiveproduct(s)optically activeproduct(s)63 for each pair, must be in correct boxesIn each of the following reactions more than one product is formed. Draw each product in its appropriate box (considering optical activity; each reaction yields at least one product of each category) and provide the NMR information requested about the starting


View Full Document

U of M CHEM 210 - Key 3

Documents in this Course
Load more
Download Key 3
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Key 3 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Key 3 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?