lejimalide B, an anticancer agent with a 24-membered ring, is isolated from a tunicate found off le Island in Okinawa. (a) Label each double bond in iejimalide B as E or Z. (b) Label each tetrahedral stereogenic center as R or S. (c) How many stereoisomers are possible for iejimalide B? CH;0 CHO OCH, HO, iejimalide B

lejimalide B, an anticancer agent with a 24-membered ring, is isolated from a tunicate found off le Island in Okinawa. (a) Label each double bond in iejimalide B as E or Z. (b) Label each tetrahedral stereogenic center as R or S. (c) How many stereoisomers are possible for iejimalide B? CH;0 CHO OCH, HO, iejimalide B

Organic Chemistry

8th Edition

ISBN:9781305580350

Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Publisher:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. Foote

Chapter18: Functional Derivatives Of Carboxylic Acids

Section: Chapter Questions

Problem 18.30P: Nicotinic acid, more commonly named niacin, is one of the B vitamins. Show how nicotinic acid can be...

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Treatment of W with CH3Li, followed by CH3I, affords compound Y(C7H14O) as the major product. Y shows a strong absorption in its IRspectrum at 1713 cm−1, and its 1H NMR spectrum is given below. (a)Propose a structure for Y. (b) Draw a stepwise mechanism for theconversion of W to Y.
Draw a structural formula for the product formed by treating butanal with each reagent. (a) LiA1H4LiA1H4 followed by H2OH2O (b) NaBH4NaBH4 in CH3OH/H2O (c) H2/Pt (d) Ag(NH3)2+in NH3/H2O (e) H2CrO4, heat (f) HOCH2CH2OH,HCl
Nicotinic acid, more commonly named niacin, is one of the B vitamins. Show how nicotinic acid can be converted to (a) ethyl nicotinate and then to (b) nicotinamide.
Identify the following compound from its IR and proton NMR spectra. C,H1,0: 'H NMR 8 3.31 (3H, s); 8 2.41 (1H, s); & 1.43 (6H, s) IR: 2110, 3300 cm-1 (sharp) Draw the compound.
gas, Cl¬CH2CH2¬S¬CH2CH2¬Cl, was used as a poisonous chemical agentin World War I. Mustard gas is much more toxic than a typical primary alkyl chloride. Itstoxicity stems from its ability to alkylate amino groups on important metabolic enzymes,rendering the enzymes inactive.(a) Propose a mechanism to explain why mustard gas is an exceptionally potent alkylatingagent.(b) Bleach (sodium hypochlorite, NaOCl, a strong oxidizing agent) neutralizes and inactivates mustard gas. Bleach is also effective on organic stains because it oxidizes coloredcompounds to colorless compounds. Propose products that might be formed by thereaction of mustard gas with bleach.
A key step in the synthesis of the narcotic analgesic meperidine (tradename Demerol) is the conversion of phenylacetonitrile to X. (a) What isthe structure of X? (b) What reactions convert X to meperidine ?
(ii) Draw the product R, including a detailed reaction mechanism for the conjugate addition reaction between the 1,3-dicarbonyl P and the a,ß-unsaturated ketone Q. Eto P OEt + Q OEt Et3N R (iv) Explain why conjugate addition is favoured over direct addition to Q in this case.
Ibufenac, a para-disubstituted arene with the structureHO2CCH2C6H4CH2CH(CH3)2 , is a much more potent analgesic thanaspirin, but it was never sold commercially because it caused livertoxicity in some clinical trials. Devise a synthesis of ibufenac frombenzene and organic halides having fewer than five carbons.
Reaction of p-cresol with two equivalents of 2-methylprop-1-ene affordsBHT, a preservative with molecular formula C15H24O. BHT gives thefollowing 1H NMR spectral data: 1.4 (singlet, 18 H), 2.27 (singlet, 3 H), 5.0(singlet, 1 H), and 7.0 (singlet, 2 H) ppm. What is the structure of BHT?Draw a stepwise mechanism illustrating how it is formed.
5-Hydroxyhexanal forms a six-membered cyclic hemiacetal, which predominates at equilibrium in aqueous solution. (a) Draw a structural formula for this cyclic hemiacetal. (b) How many stereoisomers are possible for 5-hydroxyhexanal? (c) How many stereoisomers are possible for this cyclic hemiacetal? (d) Draw alternative chair conformations for each stereoisomer and label groups axial or Also predict which of the alternative chair conformations for each stereoisomer is more stable.
Identify the following compound from its IR and proton NMR spectra. C,H1,0: 'H NMR 8 3.31 (3H, s); 8 2.41 (1H, s); & 1.43 (6H, s) IR: 2110, 3300 cm- (sharp)
4G. 4G 7:41 PM 27 4. Draw structures corresponding to the following names: (a) 2,2-Dimethylpropanoyl chloride (c) 5,5-Dimethylhexanenitrile (e) trans-2-Methylcyclohexanecarboxamide (f p-Methylbenzoic anhydride (b) N-Methylbenzamide (d) tert-Butyl butanoate