5- Hydroxypentanoic acid lactone

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. 

SYNS FEMA No. 3103 4-HYDROXYPENTANOIC ACID LACTONE 4-HYDROXYVALERIC ACID LACTONE Y-METHYL-7-BUTYROLACTONE 4-METHYL-Y-BUTYROLACTONE Y PENTALACTONE 4-PENTANOLIDE Y-VALEROLACTONE (FCC)... 

G.3) (G.3) 2(3//)-Furanone, dihydro-5-methyl-, pentano-4-lactone, tetrahydro-5-methylfuran-2-one, 4-pentanolide, 4-hydroxypentanoic acid lactone, "y-methyl-7-butyrolactone, y-pentalactone, 7-valerolactone [108-29-2] FEMA 3103 ( )- [57129-69-8] (R)- [58917-25-2] (S)- [19041-15-7]... 

Propene passed ca. 7.5 hrs. into a stirred soln. of bromodicyanomethane in methylene chloride with initial removal of oxygen and subsequent irradiation with a high-pressure Hg-lamp crude 3-bromo-l,l-dicyanobutane (Y 90%) boiled 3 hrs. with HCl (d. 1.19), the intermediate crude 4-hydroxy-2-carboxypentanoic acid lactone (5.5 from 9.2 g.) heated 3 hrs. at 145 and distilled 4-hydroxypentanoic acid lactone (Y 78% based on 3-bromo-l,l-dicyanobutane). F. e., also stereospecific ring closure, and from 1,1-dicyanocyclopropanes, s. P. Boldt, W. Thieleche, and J. Etzemuller, B. 102, 4157 (1969). 

Hydroxypentane. See s-Amyl alcohol 4-Hydroxypentanoic acid lactone. See y-... 

Synonyms 4,5-Dihydro-5-methyl-2(3H)-furanone 4-Hydroxypentanoic acid lactone 4-Hydroxyvaleric acid lactone 3-Methylbutyrolactone 4-Methyl-y-butyrolactone y-Methyl-y-butyrolactone y-Pentalactone 4-Pentanolide 4-Valerolactone Empirical C5H8O2... 

Amino-3-methyl-4-hydroxypentanoic acid lactone, Y"21.2 C6H11NO2S... 

Ci2HisBrN02, L-3-Benzylamino-4-hydroxypentanoic acid lactone hydrobromide, 35B, 86... 

The 2,5-dibromo-2,5-dideoxy-D-xylono-1,4-lactone (6) (Scheme 2) can also be selectively reduced to give 5-bromo-2,5-dideoxy-D-fhreo-pentonolactone (7) by reaction with either aqueous hydrazine as mentioned above, or by consumption of 1 mole of hydrogen [ 14]. Further reaction with hydrogen and Pd/C leads to 3-hydroxypentanoic acid by an initial reductive elimination [15]. Reduction of the primary bromine in these cases can be obtained by means of tributyltin hydride [25] to give 8. 

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. 

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. 

Dibromo-2,5 -dideoxy-D-lyxono-1,4-lactone (14) was produced on treatment of ammonium D-xylonate with hydrogen bromide in acetic acid, and on hydrogenolysis (Pd/C-Et N) it gave firstly the 5-bromide (15), then the 3-hydroxypentanoic acid (16). Similar treatment of potassium D-arabinonate gave approximately equal amounts of the D-arabino-5-bromide the L-lyxo-enantiomer... 

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