Concept explainers
(a)
Interpretation: The stereogenic center at
Concept introduction: The stereochemistry of the compound is determined by prioritizing the groups attached to its stereogenic center. The groups are prioritized on the basis of
(b)
Interpretation: The two isomeric products formed on reaction of A with
Concept introduction: Zincborohydride is a metal hydride reagent. It is a mild reducing agent which reduces
(c)
Interpretation: The reagent used to convert the A to the single stereoisomer X is to be predicted.
Concept introduction: The chiral oxazaborolidine catalysts are enantiomeric selective reducing reagent. The carbonyl group of ketones are reduced to form one stereoisomer in the enantiomeric excess.
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- Treatment of -D-glucose with methanol in the presence of an acid catalyst converts it into a mixture of two compounds called methyl glucosides (Section 25.3A). In these representations, the six-membered rings are drawn as planar hexagons. (a) Propose a mechanism for this conversion and account for the fact that only the OH on carbon 1 is transformed into an OCH3 group. (b) Draw the more stable chair conformation for each product. (c) Which of the two products has the chair conformation of greater stability? Explain.arrow_forwardThe LD50 (“Lethal Dose, 50 %”) is a value used in toxicology which gives the amount of a substance required to kill 50 % of a test population. It is usually reported based on body weight. For racemic carvone LD50 is reported as 1640 mg/kg. 1. Would it consider carvone to be toxic to an average person? Explain. 2. Would it be expected this the LD50 value to be the same for each enantiomer? Explain at the molecular level in stereochemical terms.arrow_forwardIgnoring stereoisomers, draw the two possible enols for butan-2-one (CH3COCH2CH3), and predict which one is more stable.arrow_forward
- Draw the structure of a compound with molecular C8H14 that reacts with one equivalent of H2 over Pd/C to form a meso compound.arrow_forwardA) Considering compounds 2a through 2l, identify: 1)one pair of geometric isomers 2)two pairs of enantiomers and 3)three pairs of identical molecules B) Give the names, including the configurations, of each of the geometric isomers and of each of the enantiomers identified in 1A and 1B. Draw the relevant structures. C) Sort compounds 2a, 2b, 2c, 2f and 2k in order of increasing solubility in water and briefly justify.arrow_forwardRank the following groups in order of decreasing priority. −CH=CH2, −CH3, −C≡CH, −Harrow_forward
- 4-Chloro-2-pentene has a double bond that can have either the E or the Z configuration and a stereogenic center that can have either the R or the S configuration. How many stereoisomers arepossible altogether? Draw the structure of each, and group the pairs of enantiomers.arrow_forward1, part A) We observe 6 carbon stereocenters in the molecule below. Indicate each stereocenter, and give the absolute S or R configuration. 1, part B) Indicate each stereoisomer in this molecule, and give the absolute S or R configuration. Then, indicate E or Z configuration of all alkenes in it (*ignoring aromatic ring*).arrow_forwardUse the Hammond postulate to explain why (CH3)2C = CH2 reacts faster than CH3CH = CH2 in electrophilic addition of HX.arrow_forward
- The absolute configuration of BAGO is (dextrorotatory, levorotatory, R, S). The melting point of its enantiomer will be (higher, lower, equal) than/with 197.2. The relative configuration of its enantiomer will be (dextrorotatory, levorotatory, R, S). The density of BAGO is (higher, lower, equal, twice) the density of its enantiomer.arrow_forwardShow how HC≡CH, CH3CH2Br, and (CH3)2CHCH2CH2Br can be used to prepare CH3CH2C≡CCH2CH2CH(CH3)2. Show all reagents, and use curved arrows to show movement of electron pairs.arrow_forwardDraw every stereoisomer for 1‑bromo‑2‑chloro‑1,2‑difluorocyclopentane. Use wedge‑and‑dash bonds for the substituent groups, and be sure that they are drawn on the outside of the ring, adjacent to each other. Clearly show stereochemistry by drawing the wedge‑and‑dashed bonds like the example. You should replace the X with the appropriate halide.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningOrganic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning