Concept explainers
(a)
Interpretation:
The side chain carboxyl group converted to a benzyl ester using benzyl chloride as a source of benzyl group has to be explained.
Concept Introduction:
Benzyl ester is the protecting group used for the protection of carboxyl group in the amino acids. The protecting groups are used to prevent the
(b)
Interpretation:
The deprotection of the side chain carboxyl group under mild conditions without removing the BOC-protecting group at the same time has to be explained.
Concept Introduction:
Hydrogenolysis is a
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Organic Chemistry
- A chemically modified guanidino group is present in cimetidine (Tagamet), a widely prescribed drug for the control of gastric acidity and peptic ulcers. Cimetidine reduces gastric acid secretion by inhibiting the interaction of histamine with gastric H2 receptors. In the development of this drug, a cyano group was added to the substituted guanidino group to alter its basicity. Do you expect this modified guanidino group to be more basic or less basic than the guanidino group of arginine? Explain.arrow_forwardα-Amino acids can be prepared by treating an aldehyde with ammonia/trace acid, followed by hydrogen cyanide, followed by acid-catalyzed hydrolysis. What amino acid is formed when the aldehyde that is used is 3-methylbutanal?arrow_forwardHyaluronic acid, a component of connective tissue, is the fluid that lubricates joints. It is a polymer of alternating N-acetyl-d-glucosamine and d-glucuronic acid subunits joined by β-1,3'-glycosidic linkages. Draw a short segment of hyaluronic acid.arrow_forward
- Another method to form a peptide bond involves a two-step process:[1] Conversion of a Boc-protected amino acid to a p-nitrophenyl ester.[2] Reaction of the p-nitrophenyl ester with an amino acid ester.a. Why does a p-nitrophenyl ester “activate” the carboxy group of the first amino acid to amide formation? b. Would a p-methoxyphenyl ester perform the same function? Why or why not?arrow_forwardGive the functions of the following ingredients, then name a branded/commercial skin or hair care product where the said material is used. Tetrasodium EDTA Cholesterol Silicone Oil 200/50 cst BETAINE Carbopol Ultrez D & C Red No. 17 ( CI No. 26100) Bisabolol (Alpha Bisabolol) Ceresin Wax Disodium Lauryl Sulfosuccinate Hydroxypropyl Methylcellulosearrow_forwardCholic acid is secreted in bile as an amide linked to the aminogroup of glycine. This cholic acid–amino acid combination acts asan emulsifying agent to disperse lipids in the intestines for easierdigestion. Draw the structure of the cholic acid–glycine combination,and explain why it is a good emulsifying agent.arrow_forward
- The reaction of ninhydrin with an -amino acid occurs in several steps (a) The first step is loss of water to give a triketone. Show the mechanism of the reaction and the structure of the triketone.(b) The second step is formation of an imine by reaction of the amino acid with the triketone. Show its structure. (c) The third step is a decarboxylation. Show the structure of the product and the mechanism of the decarboxylation reaction. (d) The fourth step is hydrolysis of an imine to yield an amine and an aldehyde. Show the structures of both products. (e) The final step is formation of the purple anion. Show the mechanism of the reactionarrow_forwardGlutamic acid is a naturally occurring α-amino acid that contains acarboxy group in its R group side chain. (Glutamic acid isdrawn in its neutral form with no charged atoms, a form that does not actually exist at any pH.) a.) What form of glutamic acid exists at pH = 1?b.) If the pH is gradually increased, what form of glutamic acid exists afterone equivalent of base is added? After two equivalents? After threeequivalents?c.) Propose a structure of monosodium glutamate, the common flavorenhancer known as MSG.arrow_forwardalpha-Amino acids can be prepared by treating an aldehyde with ammonia/trace acid, followed by hydrogen cyanide, followed by acid-catalyzed hydrolysis. a. Draw the structures of the two intermediates formed in this reaction. b. What amino acid is formed when the aldehyde that is used is 3-methylbutanal? c. What aldehyde is needed to prepare isoleucine?arrow_forward
- Another strategy used to resolve amino acids involves converting the carboxy group to an ester and then using a chiral carboxylic acid to carry out an acid–base reaction at the free amino group. Using a racemic mixture of alanine enantiomers and (R)-mandelic acid as resolving agent, write out the steps showing how a resolution process would occur.arrow_forwardDraw the structure of the tetrapeptide Asp-Arg-Val-Tyr. Please show the appropriate stereochemistry of the natural amino acids in the resulting peptide. Please draw all ionizable groups in their neutral form.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning