Ch 20 Ochem – Flashcards
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Provide the structure of the ylide needed to prepare 3-ethyl-3-heptene from 3-pentanone using a Wittig reaction.
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Ph3P=CHCH2CH2CH3
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What is the correct order of migration rate for the following groups in the Baeyer-Villiger oxidation reaction?
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H > phenyl > t-butyl > methyl
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What is the correct order of migration rate for the following groups in the Baeyer- Villiger oxidation reaction?
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oxirane
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A compound with formula c5h10o shows two singlets, in the 1H NMR spectrum. Which one of the following is a possible structure for this compound?
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(CH3)3CO=CH
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The 1H NMR spectrum of a compound with formula c7h14o shows two signals. Which one of the following is a possible structure for this compound?
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2,4-dimethyl-3-pentanone
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The 13C NMR spectrum of a compound with formula C7H14O shows five signals. Which one of the following is a possible structure for this compound?
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2,2-dimethyl-3-pentanone
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The 1H NMR spectrum of a compound with formula C7H14O shows a doublet at 9.2 ppm. Which one of the following is a possible structure for this compound?
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2-methylhexanal
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Provide a structure for the compound with molecular formula C5H10O and with the following spectroscopic data. IR: 1720 cm?1 1H NMR: 1.9? (triplet, I=3H), 1.7? (sextet, I=2H), 2.1? (singlet, I=3H), 2.4? (triplet, I=2H)
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2-pentanone
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Provide a structure for the compound with molecular formula c9h10O and with the following spectroscopic data. IR: 1680 cm?1 1H NMR: 1.25? (triplet, I=3H), 3.0? (quartet, I=2H), 7-8? (multiplet, I=5H)
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benzene ring with C=OCH2CH3
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Compound A on ozonolysis yields 2,6-heptanedione. What is the structure of compound A?
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1,2-dimethylcyclopentene
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Compound A on ozonolysis yields acetophenone and propanal. What is the structure of compound A?
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2-phenyl-2-pentene
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Predict the product for the following reaction. 3-methyl-1-octanol ?(PCC/CH2Cl2)
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3-methyloctanal
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Predict the product for the following reaction. 2-hexanol ?(PCC/CH2Cl2)
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2-hexanone
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Which one of the following is the strongest acid? A) benzoic acid B) 4-nitrobenzoic acid C) 4-ethylbenzoic acid D) 4-chlorobenzoic acid E) 4-hydroxybenzoic acid
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2-nitrobenzoic acid
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Which one of the following is the strongest acid? Explain your choice. A) 2,3-dimethylheptanoic acid B) 3,3-dichlorohexanoic acid C) 3-iodo-4-bromo-hexanoic acid D) 3-chloro-4-bromoheptanoic acid E) 2-fluoro-4-bromohexanoic acid
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E Fluorine is the most electronegative and is in the closest proximity of the carboxylic acid group. It will stabilize the conjugate base via an inductive effect, making it a weaker base.
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Provide the reagents necessary to carry out the following conversion. 4-ethylheptanoyl chloride ? 5-ethyl-2-octanone
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(CH3)2CuLi
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Provide the reagents necessary to carry out the following conversion. 5-phenyl-1-pentanol ? (1) 5-phenylpentanoic acid ?(2) 5-phenylpentanoyl chloride ?(3) 8-phenyl-4-octanone
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K2Cr2O7/H2SO4/H2O SOCl2 (CH3CH2CH2)2CuLi
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A compound with molecular formula c6h12o2 exhibits two singlet in its 1HNMR spectrum, at ? 1.4 (I=9) and ? 2.0 (I=3). Its IR spectrum shows a strong absorption band near 1740 cm-1. What is the structure for this compound?
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tert-butyl acetate
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Which one of the following compounds is most acidic? A) ethyl acetoacetate B) 2-butanone C) ethyl pentanoate D) 1-butanol E) 3-pentanone
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ethyl acetoacetate
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Which of the following base will completely convert 1,4-cyclohexanedione into an enolate? A) sodium hydroxide B) sodium ethoxide C) LDA D) sodium hydride
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sodium hydride LDA
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Which of the following ketones will give a positive iodoform test? A) 3-heptanone B) 3-hexanone C) cyclohexanone D) 2-pentanone E) 2-methyl-3-hexanone
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2-pentanone
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Provide the reagents necessary to convert acetophenone to benzoic acid
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1. NaOH/Br2 2. H3O
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Which one of the following compound does not undergo an aldol addition reaction in presence of aqueous sodium hydroxide? A) butanal B) 2-methylbutanal C) 3-methylpentanal D) 2,2-dimethylbutanal E) none of these
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2,2-dimethylbutanal
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Explain why CH3ONa should not be used for Claisen condensation of ethylbutanoate.
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Use of CH3ONa will result in transesterification product.
