Ch 20 Ochem – Flashcards

Unlock all answers in this set

Unlock answers
question
Provide the structure of the ylide needed to prepare 3-ethyl-3-heptene from 3-pentanone using a Wittig reaction.
answer
Ph3P=CHCH2CH2CH3
question
What is the correct order of migration rate for the following groups in the Baeyer-Villiger oxidation reaction?
answer
H > phenyl > t-butyl > methyl
question
What is the correct order of migration rate for the following groups in the Baeyer- Villiger oxidation reaction?
answer
oxirane
question
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?
answer
(CH3)3CO=CH
question
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?
answer
2,4-dimethyl-3-pentanone
question
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?
answer
2,2-dimethyl-3-pentanone
question
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?
answer
2-methylhexanal
question
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)
answer
2-pentanone
question
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)
answer
benzene ring with C=OCH2CH3
question
Compound A on ozonolysis yields 2,6-heptanedione. What is the structure of compound A?
answer
1,2-dimethylcyclopentene
question
Compound A on ozonolysis yields acetophenone and propanal. What is the structure of compound A?
answer
2-phenyl-2-pentene
question
Predict the product for the following reaction. 3-methyl-1-octanol ?(PCC/CH2Cl2)
answer
3-methyloctanal
question
Predict the product for the following reaction. 2-hexanol ?(PCC/CH2Cl2)
answer
2-hexanone
question
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
answer
2-nitrobenzoic acid
question
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
answer
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.
question
Provide the reagents necessary to carry out the following conversion. 4-ethylheptanoyl chloride ? 5-ethyl-2-octanone
answer
(CH3)2CuLi
question
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
answer
K2Cr2O7/H2SO4/H2O SOCl2 (CH3CH2CH2)2CuLi
question
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?
answer
tert-butyl acetate
question
Which one of the following compounds is most acidic? A) ethyl acetoacetate B) 2-butanone C) ethyl pentanoate D) 1-butanol E) 3-pentanone
answer
ethyl acetoacetate
question
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
answer
sodium hydride LDA
question
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
answer
2-pentanone
question
Provide the reagents necessary to convert acetophenone to benzoic acid
answer
1. NaOH/Br2 2. H3O
question
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
answer
2,2-dimethylbutanal
question
Explain why CH3ONa should not be used for Claisen condensation of ethylbutanoate.
answer
Use of CH3ONa will result in transesterification product.
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New