Organic Chemistry Questions

H 23 0 LiAlH4 NaBH4 P Q Sum of number of alcoholic groups in product P and Q is a 1 b 2 c 3 00 10500 d 5

2 Provide the missing conditions for the following transformations CI X Me CuLi NaBH4 X X Me HO Me These is the answer key to said question but I m just a bit confused how the fir mechanism is carried out I would appreciate seeing how it works Thanks

Predict the major product and draw th e mechanism for the following Friedel Crafts Acylation reactions 0 0 b AICI3 00 0 6 b QO AICI3 Chemistry St Cherry Steps AICI 3 40 42 An

Section III Paragraph Single Answer Correct 4 questions 3 0 Q 33 34 Compound A on reaction with BH3 THF followed by OH H 0 gives compound X that on further reaction gives Y Compound A on reactio with H SO4 H O gives Z It gives W on reaction with CH3COO 2Hg H C followed by NaBH H SO4 H O A W 33 Formation of Z is an example of 1 BH3 THF ii OH H O i CH COO Hg H O ii NaBH4 X A electrophilic substitution reaction C electrophilic addition reaction HBr B nucleophilic addition reaction D free radical addition reaction

Phenol 1 NaOH leq 2 D Me 1 x 3 HCN HCI AICI 4 H O r H If Q Number of organic products formed in step 2 significant product R Number of organic products formed in step 3 significant product S Steps in which aromatic electrophilic substitution has taken place Then value of Q R S is

54 A levo rotatory compound 2 chloro 2 phenyl butane is undergoing nucleophilic substitution with OH following SN mechanism The product s obtained is are a leavo rotatory 2 phenyl butan 2 ol c 1 1 Mixture of both a and b b Dextro rotatory 2 phenyl butan 2 ol d None of these

A binding energy curve is a plot of binding energy per nucleon versus atomic number In what region of the binding energy curve are the most stable elements found A in the lower left region low atomic mass B in the central top region moderate atomic mass C in the lower right region heavy atomic mass D binding energy is not dependent on atomic mass

Boxe plea he expect major pro Box 5 please indicate the reagents necessary to complete the indicated reaction If the answer for the product is a mixture of enantiomers draw one of the enantiomers and write enantiomer If the answer is a mixture of diastereomers draw all of them Students with no printer please draw a set of numbered boxes and place answer inside 1 Br OH 1 NaH 2 EtBr DMSO 2 3

10 Compound A reacts with HBr via an SN1 process leading to 3 different constitutional isomers Two of these constitutional isomers are chiral such that a total of 5 distinct isomers are obtained from this reaction Draw the structures of all 5 products 41 45 OH A 42 HBr 41 43

Boxes below please indicate the expected major pro Box 5 please indicate the reagents necessary to complete the indicated reaction If the answer for the product is a mixture of enantiomers draw one of the enantiomers and write enantiomer If the answer is a mixture of diastereomers draw all of them Students with no printer please draw a set of numbered boxes and place answer inside 2 w 4 the indicated reaction For

lion 1 5 Then rium 9 Major product of the given reaction is 1 8 Br K Br HBr Product 2 F Br Br

Which of the following monosaccharides will form D glucaric acid structure below upon oxidation with nitric acid Cooll I OH HOT H H OH H OH COOH Select one OA OB O C CH OH D Glucitol H OH HOR OD A and B OE A and C H OH CH OH CH 01 L Glucose H OH H OR HO H H OH HOHO HORO D Glucose ON HOT H HU TOH H TOH CH OH

A sunburn prevention agent must be non toxic non staining non volatile reasonability wate soluble It should filter of the burning rays of sunlight Given structure is one such compound Which methods for synthesis of above compound starting from m dimethoxybenzene A 1 Ph COCL n dil NaOH B 1 Cong H1 PC On C F COC sace II D All of these

4 5 Explain the difference between Buna N and Buna S 6 Arrange the following polymers to creasing order of their intermolecular fo Nylon 6 6 Buna S Polythene 0 Nylon 6 Neoprene Polyvinyl chloride

12 Identify compound s in which gauche conformer is more stable than staggered B Chloropropane C Ethylene glycol D Succinic acid A 1 2 Difluoroethane No 42 JA OB OC OD

Partial reduction b Partial oxidation c Complete reduction d Complete oxidation 2 A Define electron gain enthalpy Explain why group 17 elements have large egative electron gain enthalpies and group 18 elements have high positive electron gain enthalpies 3 marks

70 Carbonyl compounds when treated with sodium bisulphite cc solution generally a crystalline sodium bisulphite addition product is formed but which of the following carbonyl compound not forms crystalline addition product a HCHO b CH3CHO Na HS c CH3COCH 3 71 Main product of the reaction is bu oby d C H5COC H5 all aldeh methyl ke

31 A student forgot to add the reaction mixture to the round bottom flask at 27 C but instead he placed the flask on the flame After a lapse of time he realized his mistake and using a pyrometer he found the temperature of the flask was 477 C What fraction of air would have been expelled out a 60 b 30 c 100 d 75

For the questions below please indicate the expected major product for the indicated reactio If the answer for the product is a mixture of enantiomers draw one of the enantiomers and wri enantiomer If the answer is a mixture of diastereomers draw all of them Students with no printer please draw a set of numbered boxes and place answer inside 1 Br NaCN DMSO

1 Among the given pairs in which pair first compound reacts faster than second compound in S SN1 reaction a CH3 CH2 CH CH2 Br or CH3 CH 2 CH CH3 THE Br CH 3 CH 3 b CH3 C CH CH or CH3 CH CH CH3 Br Br C Br 6 6 or CH 3 1 d CH3 C CH3 11 ve Br Br CH 3 or CH3 C CH 3

Use the molecular orbital diagram for the diatomic molecule SiN below to determine what will happen to the silicon nitrogen bond if you make the neutral molecule into the anion SiN E LL 1 SIN 1 11 11 t 11 111 11 The bond in SiN will be longer and weaker The bond in SiN will be shorter and weaker The bond in SiN will be longer and stronger The bond in SiN will be shorter and stronger

Please solve the following 18 electron problem using two types of ionic and covalent models Ph P Ph OC OC OC RO Os BH RO Au Au co OR OR OR RIC W R CH O Co Co 8 Br CH t Bu Au t Au 1 CH3 Rh O Rh R

hich of the following pair s is are resonating structures e CH CH CH CH CH3 and CH CHCH CHCH e CH CH CH CH CH and CH CH CHCH CH CH CH CH and CH CHCH 15 CH CH CH CH CH and CH CH CH CH CH

49 How many terminal alkynes isomers are possible for the formula CeH10 O No 49

H of D H3C OH Which statement is correct SOCI SOCI Pyridine X y x and y are superimposable mirror images x and y are non superimposable mirror images O x and y are neither mirror images nor super imposable x and y are structural isomers

27 The back side attack on 2 bromobutane by methoxide CH 30 gives the product shown below Which Fischer projection represents 2 bromobutane used as the reactant in this reaction e elxb Et a Me H HD HBr HD OCH3 product Et Me H 1 d Et b H Br Me Me c Br H Et Br Me H H Et d Me

c LiAlH4 ether 34 Which of the following reactions gives an dialkyl oxonium salt a Ethyl alcohol sodium metal b Diethyl ether hydrochloric acid c Tertiary amine alkyl halide d Nitromethane sodium metal chon W ridation with per iodic acid gives

1 Both iv v 3 iii 4 v 6 In Reimer Tiemann reaction molecular weight of 26 Reimer Tiemann phenol increases by 1 28 2 29 2 ii 3 27 4 31 OH 1 a iv a v 3 iii 1 28 2 29 2 ii 4 v 3 27 4 31

169 The final products of oxidation of isopropyl alcohol are a CH3COCH HCOOH b CH CH COOH HCOOH e CH3COOH HCOOH 0 CUOL C d CH3COOH CH3CH COOH Cherchon CH

6 A chiral C H O ether reacts with hot HI to give a C H I product Treatment of this with hot KOH in ethanol produces 1 3 pentadiene What is the structure of the original ether 10 10 2 CH A B CH Ja O C CH D H C CH

3 3dimethyl but 1 ene on reaction with aqueous mercuric acetate followed by reduction by sodium borohydride gives 2 2 dimethyl butan 1 ol 3 3 dimethyl butan 1 ol 3 3 dimethyl butan 2 ol 2 3 dimethyl butan 2 ol

Pick the one with different degree of unsaturation A B C D

Which medicine is produced as a nitrate salt O A serotonin B O C securinine O D mexamine O E reserpine physostigmine Strychnos nux vomica is rich in one of these alkaloids Select the right one O A physostigmin O B reserpine O C strychnine D securinine

1 Complete the following chemical equations for the following aldehydes ketones undergoing aldol addition followed by condensation For the starred reactions draw the full reaction mechanisms a b NaOH H O NaOH H O NaOH H O NaOH Heat NaOH Heat NaOH Heat

For the reaction 2 N O5 4 NO2 O2 rate of reaction is given by 1 d N 05 dt NI 2 2d 05 dt d NO dt hr m d 0 dt

Select the best reagent for the conversion 310 H5C 0 O CH OH OH i PCL5 ii y iii H3O x is LiAlH4 x is NaBH4 y is NaBH4 CH OH y is B H THE H C CH CH CH 2 CH COOH C H OH CH OH OH H C CH CH2 2 CH Hs COOH Cooc s OH

How many of the following elimination takes place via E1CB mechanism Br OH H C CH CH C CH3OH H3C CH CH C CH3 MeO Ph O C H5O A NO 2 H MeO A H3C S CH CH OPh Ph NaOD D 0 A NO 2 01S H C S CH CH

Explain the reaction shown below Include the following pieces in your explanation a Identify the electrophile and the nucleophile Draw a curved arrow mechanism for this reaction Assume an acidic work up Explain the electron flow c 1 Indicate any regiochemical or stereochemical preferences MeO LIAIH4 M 0 OH Tro

1 Which of the following statements about protein secondary structure is not true a Secondary structure gives the location and directionality of the backbone of proteins not R groups b Inter chain interactions between two parts of a polypeptide chain can occur in beta sheets c Protein secondary structure in maintained by hydrogen bonding between R groups and the backbone of proteins d Alpha helices are all right handed

For the following reactions please deduce the structures of compounds B and C Spectral data for compound Ca summarized below 12 OH MgCl H O autoclave 230 C 2 h B C Mass spectrum m z 234 p IR Nujol 1870 sh 1940 m and 1780 s cm 1H NMR CDC13 8 0 98 d J 6 8 Hz 3H 1 08 d J 6 8 Hz 3H 1 36 m 4H 1 46 s 3H 2 60 septet J 6 8 Hz 1H 2 80 d J 9 Hz 1H 3 20 d J 9 Hz IH 6 01 d J 8 5 Hz 1H 6 10 d J 8 5 Hz IH

4 40 The product in the given reaction is CH OH Br 3 ch Cu27 a c c CH e CH H SO4 Mon nono d methyl isocyanide Product To b d CH3 CH con Cen on anzion CM2 CH 1 CH CA NO Cna airol

C 1 In which of the following bond angles on sp hybridized are not contracted due to lone pair of electron 6 110 a OF b H O c CH3OCH3 3 R N d CH OH M 10 with ammonia and passed over

1 Compare relative stability of following resonating structures CH 0 CH CH C N a e CH 0 CH CH C N a a b c d b a c d b se CH O CH CH C N b CH O CH CH C N d c a d c b 6 d c d b a

Number of hyperconjugation resonance structures of BH3 CO x Number of hyperconjugation resonance structures of BH3 PF3 Y Choose the correct relationship O x y 3 O O O x y 3 x y none of these

A i 0 CH Cl 78 C ii Zn H O CHJCHO CH3 CO CH3 CO In the above reaction the compound A is 1 CH CH CH CH CH 2 CH C CH CH CH 3 CH3 CH C C CH3 2 4 CH3 CH C CH CH

D Which of the following is most reactive toward S N2 Cl Cl a CH3 b c reaction wollot orb to ridw Cl Cl NO2 1 Cl naim in which pair first compound reacts faster than second compou

CH 20 The major product in the reaction CH CH C Br CH CH Na CH CH X CH 1 CH3 C C CH3 2 3 CH CH C CHCH CH C H OH 2 CH CH CH CH T CH CH3 is w DO CH 4 CH CH C CH3h C CH CH3 C H

96 An alcohol is not oxidised in alkaline or neutral solution b in acidic solution it is turned first to acetone and then acetic acid It is a a primary alcohol c tertiary alcohol b secondary alcohol d none of these

110 Vapours of an alcohol were passed over hot reduced copper On It gave an olefin The alcohol is a primary c tertiary b secondary d none of these 24 CU 2

Identify D in the following reaction sequence SOCL Mg Ether HCHO H 0 CH3CH OH A B C D a n Butyl alcohol b Propanal c d n Propyl alcohol Butanal