2-hydroxypentanoic acid

Almotriptan has also been synthesized via decarboxylation of the carboxylic acid intermediate 65, but a detailed preparation of 65 was not provided in the patent literature (Scheme 22)." The patent indicates that the carboxy indole 65 was prepared according to the method of Gonzalez.°° Thus, (2-oxo-tetrahydro-3-furanyl)-glyoxylic acid ethyl ester (62) was heated in aqueous H2SO4 to give 2-oxo-5-hydroxypentanoic acid in situ, which was treated with hydrazine 59 to produce hydrazone 63. Fischer cyclization of 63 using HCl gas in DMF gave the lactone 64, which was converted to carboxylic acid 65. Decarboxylation of 65 was catalyzed by cuprous oxide in quinoline at 190 °C to afford almotriptan (5)." ... 

Following is a structural formula of 5-hydroxypentanoic acid and the five-membered lactone (cyclic ester) it forms. 

Glutamic acid 1,5-Pentanediol, 2-amino-1,5-pentanediol, 4-amino-5-hydroxypentanoic acid, 4- amino-butanoic acid, 5- methyl-2-pyrrolidinone, 5 -hydroxynorvol ine, 5-(hydroxymethyl)-2-pyrrol idinone, pyroglutamic acid, 5-caprolactone Food additives, polymers, solvent Hermann, 2003 Feuchtenberger etal., 2005 Corma etal., 2007... 

Problem 21.9 If 5-hydroxypentanoic acid is treated with acid catalyst, an intramolecular esterification reaction occurs. What is the structure of the product Intramolecular means within the same molecule.)... 

From a structural standpoint, these compounds consist of a trichothecane sesquiterpene diol linked through ester bonds to a diacid derived from esterification of the ( )-acid of a (Z, )-muconic acid with a 5-hydroxypentanoic acid segment (containing various substitution patterns). As the synthesis of the sesquiterpene diol unit is beyond the scope of this chapter, we have limited discussion to the methods employed for formation of the macrocyclic ring of these substances. Papers concerning the construction of the various trichothecane diol systems may be found by consulting the references cited in this section. 

Nitratopentanoic acid 5-Oxopentanoic acid 5-Hydroxypentanoic acid Glutaraldehyde... 

Which monomer would give a greater yield of polymer, 5-hydroxypentanoic acid or 6-hydroxyhexanoic acid Explain your choice. 

Kaneko, H. and M. Harada The aroma of cigar tobacco. Part III. Isolation and synthesis of R-(-i-)-3-isopropyl-5-hydroxypentanoic acid Agr. Biol. Chem. Japan 36 (1972) 658-662. 

Just as esters react with aqueous acid or aqueous hydroxide to regenerate the acid and the alcohol precursors (see Section 20.2), lactones react to give the hydroxy acid. Hydrolysis of 89, for example, gives 5-hydroxypentanoic acid. In the case of five-membered ring lactones, the lactone tends to be more stable than the hydroxy acid, so it is common for this equilibrium to favor the lactone. 

Amino-5-hydroxypentanoic acid, A9.6 2-Amino-4-hydroxypentanoic acids, A 6.5, A 6.6 C3H N03S... 

Butyl-5-hydroxypentanoic acid lactone, A 26.8 5-Oxo-2-isopropylhexanal, T 10.8 xo-Brevicomin, Y 3.4... 

Thianaphthenyl)-propoinic acid, A48.3 3-Phenyl-5-hydroxypentanoic acid lactone. 

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