. Which of the following compounds corresponds to the spectral data given below? one of these. The reaction energy diagram given below corresponds to which of the following reactions? TS TS TS Br + R RI RI P Br none of these a & b RX. ow many chiral centers are present in the molecule given below? Paroxetin (PAXIL, an antidepressant) a) none b) c) d) F
. For the reaction given below, which of the following statement(s) is (ar true? l a) The electrophilic reagent is l b) The kinetic product is a racemic mixture c) Products I and III are thermodynamic products d) a & c a, b & c I l l II l III IV. A Fisher projection for cilastatin, a dipeptidase inhibitor, is: B S ilastatin S S S S b & d. Which stereoisomer(s) of,-dimethyltetrahydrofuran is (ar meso? a) S, S b) R, R and S, S c) S, R d) R, S and S, R none of these
7. In the MR spectrum of the alcohol given below, the a proton will appear: a a) as a singlet between.-8. ppm b) as a singlet between.-. ppm c) as a doublet between.-8. ppm d) as a triplet between.-8. ppm anywhere 8. Which of the following compounds contains a chiral center with an R configuration? hloramphenicol c) d) S Sertraline (ZLFT) l l ephalexin Lysergic Acid All of these 9. Which of the follow mass spectra corresponds to ortho-dichlorobenzene? A l l ortho-dichlorobenzene none of these
0. Lysergic acid has an optical rotation of +0. Which of the following compounds has an optical rotation of 0? a) b) Lysergic Acid B b & d. Which of the following alkene(s) will give rise to the product mixture given below when reacted with Br under kinetic conditions? Br Br Br B Br Product Mixture b & c. Which of the following statements is true regarding the stereochemical relationships of compounds A-? A B a) Structures and are meso compounds b) Structure and are diastereomers c) Structures A and are diastereomers d) Structures B & are positional isomers b & d
. ow many stereoisomers are formed upon reaction of + (kinetic conditions) with R-,- dimethylcyclobutene? a) b) c) 8 d) R-,-dimethylcyclobutene A. A diastereomer of setraline, an antidepressant is: Sertraline (ZLFT) l l l l c) d) l l l l l l a & b. Which of the following pairs of compounds could be distinguished by IR spectroscopy? a & c A none of these
. The rate-determining step of the reaction depicted in the reaction energy diagram given below involves which of the following transformation(s)? TS R TS TS RI RI a) R -->RI b) RI --> RI c) RI --> P d) a & b All steps of the reaction occur at the same rate RX P 7. The thermodynamic product(s) of the reaction given below: a) is derived from a alkyl carbocation b) is derived from a allylic carbocation c) is derived from a allylic carbocation d) is derived from a allylic carbocation c & d equiv + 8. Isomethadol is an analgesic agent whose R, S stereoisomer has potent analgesic activity. one of the other stereoisomers of this compound have analgesic activity. Which of the following compounds corresponds to the active form of isomethadol? Isomethadol ( ) ( ) B ( ) ( ) a & c
7 9. An absorbance value of 0.7 was obtained in the UV spectrum of ephedrine at max =. The concentration of this solution is: (Standard curve data is provided in the table below. Assume a pathlength = ) Standard urve ata oncentration A. X 0 - M 0.. X 0 - M 0.87. X 0 - M.. X 0 - M.7 a).79 X 0 - M b).77 X 0 M c).8 X 0 - M d). X 0 - M none of these 0. Reaction of the molecule below with equivalent of Br under kinetic conditions will provide (a) product(s) that contain(s): S a) a secondary alkyl bromide b) a cis double bond c) a trans double bond d) a & c all of these. Reaction of -chloro--ethyl--methylhexane with acid gives -chloro--ethyl--methylhexane. This reaction type is: a) an addition b) a substitution c) an elimination d) a rearrangement none of these. A transition state structure in a single-step, exothermic reaction: a) is lower in energy than the products b) is lower in energy than the reactants c) leads to a reaction intermediate d) is closer in energy to the reactants is closer in energy to the products. The most stable reaction intermediate given below is: All of these are equally stable. A
8. The major kinetic product of the reaction of -T with l is: l l l l -T l. Which of the following compounds will react the fastest with Br? I II III a) All react at the same rate b) I &II c) I & III d) II & III II
9 hemical Shift Ranges for Protons in MR Spectroscopy Range Type of Proton 0-. ppm atoms bonded to sp carbons where the sp carbons are only bonded to other sp carbons and hydrogen (alkanes). -. ppm atoms bonded to sp carbons where the sp carbon is bonded to at least one sp and no heteroatoms (allylic, benzylic, -). -. ppm atoms bonded to an sp that is also bonded to at least one heteroatom. -. ppm atoms bonded to sp carbons of alkenes (not aromatic sp carbons). - 8. ppm atoms bonded to sp carbons of an aromatic ring 0 - ppm atom bonded to an sp carbon atom of the carbonyl group of an aldehyde or atom bonded to the sp oxygen of a carboxylic acid. Anywhere atom directly bonded to a heteroatom other than the oxygen atom of a carboxylic acid. Show up as a broad singlet Absorbance Ranges for Bond Types in IR Spectroscopy Absorbance Range Functional Group lass 80-90 cm - Alkanes, Alkyl Groups ( sp -) 00-00 cm - Alkenes, Aromatics ( sp -) 0-80 cm - Alkenes (=) 00 cm - Alkynes ( sp -) 00-0 cm - Alkynes (=) 00-800 cm - Alkyl alide (-X, X = halogen) 00-0 cm - Alcohol, arboxylic acid (-) 00 cm -, 00 cm - Aromatic (=) 80-80 cm - arbonyl (=, ketone, aldehyde, ester, amide, carboxylic acid) 00-00 cm - Amines (-) 0 cm - itro (- ) atural Abundances of Atoms ommon in rganic Molecules Atom atural Abundance 98.89%.% 0.00% l 7% 7 l % 79 Br % 8 Br 9%