Chemistry 212Name ______
Organic Chemistry IIApril 11, 1997
Please write all of your answers on the examination booklet. Each question or part of a question is worth five (5) points.
11Of the following combinations of reagents, the one that does not lead to 3-methyl-3-pentanol is:
11Methyl Grignard + 3-pentanone
21Ethyl Grignard + ethyl acetate
31s-Butyl Grignard + ethylene oxide
413-methyl-2-pentene + aqueous sulfuric acid
22A crossed aldol reaction between benzaldehyde (PhCHO) and acetone (CH3COCH3) would be expected to give:
33The product expected, after workup, from the reaction of phenyl Grignard reagent (PhMgBr) with acetaldehyde (CH3CHO) is:
13PhCH2OH
23PhCH(OH)CH3
33PhCH3CH2OH
43PhC(OH)(CH3)2
44The following proposed synthesis fails to give the desired product because:
14it is not possible to make a Grignard reagent from an alkyl chloride
24the Grignard reagent produced in the first step attacks the starting material
34formaldehyde is not sufficiently reactive to be attacked by a Grignard reagent
44transesterification occurs instead
55The -hydroxyalcohol produced in the first stage of the aldol reaction of butanal in base is:
66In the Reformatsky reaction:
16an -bromoester is produced
26a -hydroxyester is produced
36a zinc enolate anion is produced by transmetallation of a Grignard reagent
46zinc metal is used to reduce an -bromoester to the ester
77Treatment of ethyl formate (HCO2CH2CH3) with methyl Grignard (CH3MgBr) produces:
172-propanol and ethanol
27acetone and ethanol
371-propanol and ethanol
47ethanol as the only organic product
88The carbonyl group most reactive toward nucleophilic acyl substitution is found in:
18an acid chloride
28an acid anhydride
38an ester
48an amide
99Which of the following reactions does not produce the alkene shown at the right,
1010To prepare leucine [(CH3)2CHCH2CH(NH2)CO2H] by a Strecker synthesis requires which carbonyl compound as the starting material:
110(CH3)2CHCH2CHO
210(CH3)2CHCH2C(O)CH3
310(CH3)2CHCHO
410(CH3)2CHCH2CO2H
1111The major product produced upon treatment of -phenylacetamide with bromine in aqueous base is:
1212When cyclobutylmethanol is treated with HBr, a ring expansion takes place in which cyclopentyl bromide is produced. The driving force for this rearrangement is:
112formation of a tertiary carbocation instead of a primary carbocation in the rate determining step
212formation of a secondary carbocation, with relief of ring strain, instead of a primary carbocation in the rate determining step
312formation of a secondary radical, with relief of ring strain instead of a primary radical in the rate determining step
412formation of a tertiary radical instead of a primary radical in the rate determining step
1313Subjecting 3-pentanone to the conditions of a Beckman rearrangement (sequential treatment with hydroxylamine and aqueous sulfuric acid) produces:
1414Wagner-Meerwein rearrangement takes place through a:
114carbocationic intermediate
214carbanionic intermediate
314carbene intermediate
414radical anionic intermediate
1515The expected product of a Claisen rearrangement of Z-1,5-heptadiene is:
1616An isocyanate has the structure
116R-CONH2
216R-N=C=O
316R-C=N=O
416R-O-C=NH
1717Of the following, the reaction that is nota pericyclic reaction is
117condensation
217cycloreversion
317electrocyclization
417sigmatropic rearrangement
1818In the benzilic acid rearrangement shown here, the group that migrates to an adjacent carbon atom is:
118phenyl
218C=O
318benzyl
418CO2H
1919In order to prepare
in a crossed Claisen condensation with dimethylcarbonate ((CH3O)2CO), the required coreactant is
119methyl acetate (CH3CO2CH3)
219propanal (CH3CH2CHO)
319methyl propanoate (CH3CH2CO2CH3)
419acetaldehyde (CH3CHO)
2020Of the following structures, that which represents the cyanohydrin of acetophenone (PhCOCH3) is
120PhCHOHCH2CN
220PhC(OH)(CN)CH3
320PhCHCNCH2OH
420PhCH(CO2H)CH2OH