1. How many chiral centers are present in atorvastatin (LIPITOR), a drug used for lowering serum lipid levels?

Transcription

1 1 1. ow many chiral centers are present in atorvastatin (LIPITR), a drug used for lowering serum lipid levels? a) none b) 1 c) 2 d) 3 4 torvastatin (LIPITR) F 2. Reaction of alloclamide, a drug used as a cough suppressant, with l, under kinetic conditions, will provide which of the following as the major product(s) of the reaction? l l lloclamide l l b & c 3. n absorbance value of was obtained in the UV spectrum at max = 235 for the compound given below. The concentration of this solution is 5 X 10-5 M. The molar absorbtivity of this compound is: (ssume a pathlength = 1) D a) 470,000 b) 364 c) 73,437 d) 12,900 none of these

2 2 4. Which of the following stereoisomers of exametazime, a diagnostic agent used to monitor cerebral blood flow, is(ar a meso compound(s)? a) 3R, 9S and 3S, 9R b) 3R, 9R and 3S, 9S c) xametazime has no chiral centers d) one of these stereoisomers are meso ll of these stereoisomers are meso xametazime 5. The following information for ropivacaine is provided in the Merck Index (12th edition, p. 1421). Which of the following statements is true related to this drug? B a) Ropivacaine is a d- enantiomer. b) Ropivacaine s enantiomer has an optical rotation of c) The parent peak in the mass spectrum of ropivacaine would appear at 74. d) The IR spectrum of ropivacaine would not have a peak in the region cm -1. a & b

3 3 6. The molecule given below contains: a) an internal alkyne and a trans, disubstituted alkene b) an internal alkyne and a monosubstituted alkene c) a terminal alkyne and a trisubstituted alkene d) a terminal alkyne and a trans, disubstituted alkene a terminal alkyne and a cis, disubstituted alkene 7. Fisher projection for hopantenic acid, a cerebral activator is: opatenic acid a) b) none of these 8. In the proton MR spectrum of chloramphenicol, the a protons will appear: 2 a a hloramphenicol a) as a doublet between ppm b) as two singlets between ppm c) as a triplet between ppm d) as two doublets between ppm as a singlet between ppm

4 4 9. The max values for a series of compounds are given below. Which of the following compounds would be expected to have a max value of ~295nm? ompound max 205nm 3 205nm 254nm 332nm 332nm b or d Which of the following compounds will react the fastest with in an electrophilic addition reaction? 3 2 B a & c will react at the same rate 3 a, b & c will react at the same rate 11. Which of the following statements is true regarding the isomeric relationships of compounds -D? B a) Structures and B are enantiomers b) Structure and D are positional isomers c) Structures and are identical and meso d) Structures and D are enantiomers b & c 3 3 D

5 5 12. diastereomer of cephalexin, an antibiotic is: 2 S 2 S 2 S ephalexin 2 S 3 2 S 3 all of these 13. Which of the following compounds has the same melting point? I III II IV a) I & II b) I & IV c) IV & V d) IV & VI II & III 3 3 V 3 3 VI 14. The electrophilic addition reaction, given below, will provide: 3 l a) a meso compound and a pair of enantiomers b) four stereoisomers c) a product with no stereochemistry d) a meso compound and a pair of diastereomers a single enantiomer B

6 6 15. lectrophilic addition reactions may occur in molecules with more than one alkene functional group. If only one equivalent of the electrophilic reagent (i.e. hydrohalic acid) is available, then only one of the alkene functional groups will react. Which of the following products will form under thermodynamic conditions in the electrophilic addition reaction outlined below? 1 equivalent of I II a) I b) I & II c) II & III d) I & III IV & IV D III IV 16. The reaction energy diagram, given below corresponds to which of the following reactions? l 3 3 l Viquidil (Vasodilator) ugenol l 3 l Latanoprost (nto-glaucoma) a & b 17. The major monochlorinated product that forms upon treatment of 1,1,2-trimethylcyclopentane with l 2, h under kinetic conditions is: a) 2-chloro-1,1,2-trimethylcyclopentane b) 1-chloro-2,2,3-trimethylcyclpentane c) 1-chloro-2,3,3-trimethylcyclopentane D d) 1-chloro-1,2,2-trimethylcyclopentane 1-chloro-1,1,2-trimethylcyclopentane

7 7 18. Which of the following compounds has an R configuration? 3 I II 2 S a) I b) I & II c) III d) IV I & IV III IV 19. Which of the sugars given below represent a D- isomer? I II III IV a) I & II only b) II & III only c) I, II & III only d) II, III, & IV only I, III & IV only D 20. Which of the following pairs of compounds could be most easily distinguished by IR spectroscopy? c) d) 3 3 c & d

8 8 21. Which of the following mechanistic steps represents the propagation step in a kinetically-controlled radical chlorination reaction of 2-methylheptane? a) l l b) l l c) l + l d) l + l l + l 22. The rate-determining step of the reaction described by the reaction energy diagram given below is: a) SM RI 1 b) RI 1 RI 2 c) RI 2 P d) TS 1 TS 2 TS 2 TS 3

9 9 23. Which of the following compounds is most consistent with the spectral data given below? Which of the following compounds is the most stable? c) d) 25. The parent peak in the mass spectrum given below is: a) b) B c) d) D

10 10 hemical Shift Ranges for Protons in MR Spectroscopy Range Type of Proton ppm atoms bonded to sp3 carbons where the sp3 carbons are only bonded to other sp3 carbons and hydrogen (alkanes) ppm atoms bonded to sp3 carbons where the sp3 carbon is bonded to at least one sp2 and no heteroatoms (allylic, benzylic, -) ppm atoms bonded to an sp3 that is also bonded to at least one heteroatom ppm atoms bonded to sp2 carbons of alkenes (not aromatic sp2 carbons) ppm atoms bonded to sp2 carbons of an aromatic ring ppm atom bonded to an sp2 carbon atom of the carbonyl group of an aldehyde or atom bonded to the sp3 oxygen of a carboxylic acid. nywhere atom directly bonded to a heteroatom other than the oxygen atom of a carboxylic acid. Show up as a broad singlet bsorbance Ranges for Bond Types in IR Spectroscopy bsorbance Range Functional Group lass cm -1 lkanes, lkyl Groups ( sp3 -) cm -1 lkenes, romatics ( sp2 -) cm -1 lkenes (=) 3300 cm -1 lkynes ( sp -) cm -1 lkynes (=) cm -1 lkyl alide (-X, X = halogen) cm -1 lcohol, arboxylic acid (-) 1600 cm -1, 1500 cm -1 romatic (=) cm -1 arbonyl (=, ketone, aldehyde, ester, amide, carboxylic acid) cm -1 mines (-) 1540 cm -1 itro (- 2 ) atural bundances of toms ommon in rganic Molecules tom atural bundance % % % 35 l 75% 37 l 25% 79 51% 81 49%