Exam 1. Org. Chem., 242 2014 Winter Name (print):_____________________________________ ( C ) 1) 1-Methylcyclopentanol is classified as ________. A) a primary alcohol B) a secondary alcohol C) a tertiary alcohol D) a phenol E) an enol Answer: C ( A ) 2) Provide an acceptable name for the compound below. (CH3)2CHCH2OH A) 2-methylpropan-1-ol B) 2-methylpropan-3-ol C) 2-methylpropan-2-ol D) butanol Answer: A ( D ) 3) Which of the following terms best describes the reactive nature of a Grignard reagent? A) carbocation B) free radical C) electrophile D) nucleophile E) carbene Answer: D ( D ) 4) Reaction of ethylmagnesium bromide with which of the following compounds yields a primary alcohol after quenching with aqueous acid? A) ethyl acetate B) CH3CHO C) (CH3)2CO D) ethylene oxide (epoxide) E) n-butyllithium Answer: D ( B ) 5) Provide the major organic product of the following reaction. Answer: A) B) C) D) ( C ) 6) Which of the following alkyl halides would be suitable to use when forming a Grignard reagent? A) BrCH2CH2CH2CN B) CH3COCH2CH2Br C) (CH3)2CH2CH2Br 1 stepwise mechanism for the following reaction (the last step is H2O workout) CH3COCl + 2 PhMgCl Answer: 9) Provide the major organic product of the reaction below. Draw the organic product you would expect to isolate from the following reaction CHO + NaBH4 → answer: 11. Draw the organic product you would expect to isolate from the following reaction O O O + LiAlH4 answer: ( B ) 12) Classify the reaction below as an oxidation. what general class of product results? A) primary alcohol B) secondary alcohol C) tertiary alcohol D) ether E) aldehyde Answer: B 8) Provide a detailed. or neither. PhCO2H → PhCH2OH A) oxidation B) reduction 2 . Answer: 10. a reduction.D) H2NCH2CH2Br E) all of the above Answer: C ( B ) 7) When a ketone is treated with LiAlH4 followed by addition of H2O. ZnCl2/HCl D) 1. the product formed is: A) a single enantiomer. D) an achial compound. H2SO4/heat C) 1. pyridinium chlorochromate 2. t-butoxide/t-butanol E) 1. E) none of the above Answer: A ( E ) 15) Which of the following reactions or series of reactions would reduce 3-metylbutan-2-ol into 3-methylbutane? A) 1. C) a mixture of diastereomers. TsCl/pyridine 2. TsCl/pyridine 2. H2SO4 D) KMnO4 E) LiAlH4 Answer: B ( A ) 14) When (R)-butan-2-ol is treated with TsCl in pyridine. B) a racemic mixture. NaOCH3 2.C) neither Answer: B ( B ) 13) Which of the following reagents is the best choice for oxidizing a primary alcohol to an aldehyde? A) H2CrO4 B) pyridinium chlorochromate (PCC) C) Na2Cr2O7. ZnCl2/HCl 2. LiAlH4 Answer: E ( A ) 16) Through what basic mechanism is 1-methylcyclohexanol converted to 1-bromo-1-methylcyclohexane upon treatment with HBr? A) SN1 B) SN2 C) E1 D) E2 E) radical chain Answer: A ( A ) 17) What compound results when 1-butanol is treated with P/I2? A) CH3CH2CH2CH2I B) racemic CH3CH2CHICH3 C) CH3CH2CH2CH2OP(OH)2 D) CH3CH2CH2CH2PI2 E) Alcohols don't react with P/I2. Answer: A ( B ) 18) What class of organic compound is the major product of the acid catalyzed reaction of an alcohol with a carboxylic acid? A) ether 3 . KMnO4 B) 1. conc. Answer: This is a pinacol rearrangement reaction where the most stable carbocation would be formed at the tertiary 4 . which reaction is preferred and why? A) Reaction B is preferred because the oxidation step works best for primary alcohols. CH3(CH2)6CH2OH + HBr → Answer: 21) Provide the structure of the major organic product in the reaction below. C) Reaction A is preferred because the formation of the carbocation would be stabilized in the benzylic position. B) Reaction A is preferred over reaction B because no elimination reactions. Answer: B 20) Predict the major product of the reaction below and provide a stepwise mechanism which accounts for its formation. D) Reaction B would be preferred because Iodine is a better leaving group for the SN1 reaction. E) There is no difference in these two reactions -. PhCH2CH(OH)CH3 Answer: PhCH2CHClCH3 22) Predict the major product of the following dehydration reaction.B) ester C) thiol D) nitrile E) sulfonate ester Answer: B ( B ) 19) In the formation of the following ether.they would give approximately the same yields. Answer: 1. (From HWs) Show how you could convert (S)hexan-2-ol to all the following compounds (only write the needed reactants. H3O+ 5. no mechanisms needed). ether 3. Answer: 5 . _________________SOCl2____________________ a) (S)-2-chlorohexane ____Make tosylate. displace with bromide________ b) (R)-2-bromohexane ____make tosylate.position in the ring. displace with hydroxide_______ c) (R)-hexan-2-ol 2) What series of synthetic steps could be used to carry out the transformation shown below? (draw all the reaction reagents and intermediates). PBr3 or HBr 2. Mg. reasonable stepwise mechanism for the reaction below. CH3CH2CHO 4. PCC or Na2Cr2O7 or KMnO4 3) Provide a detailed. Bonus questions (6 points each) 1.