Methyl -2-hydroxypentanoate

Sitophilate [1-ethylpropyl (2S,3 )-2-methyl-3-hydroxypentanoate, 24] is the male-produced aggregation pheromone of the granary weevil (Sitophilus granarius). Its racemate is also bioactive. Almeida synthesized ( )-24 by diaster eoselective hydrogenation of the Baylis-Hillman adduct A to B as shown in Scheme 37 [60]. This high diastereoselectivity could be observed only with TBS-protected ester A to give pure B. 

K Mori, H Mori, H. Sugai. Biochemical preparation of both the enantiomers of methyl-3-hydroxypentanoate and their conversion to the enantiomers of4-hexanol-ide, the pheromone of Trogoderma glabrum. Tetrahedron 41 919-925, 1985. 

Preparation of the Enantiomers of Methyl 3-Hydroxypentanoate. A mutant of Candida rugosa oxidizes pentanoic acid to give (R)-3-hydroxypentanoic acid of 93% e.e. (19). The corresponding methyl ester 18 can be purified via its crystalline 3,5-dinitrobenzoate to give (R)-18 of 100% e.e. as shown in Figure 6 (20). 

Figure 6. Preparation of the enantiomers of methyl 3-hydroxypentanoate. Reagents a) Candida rugosa b) MeOH-H2S04 (80%) c) 3,5-(02N) C6H3C02H, DMAP, DCC/CH2C12 recrystallization d) K0H/THF-Me0H-H20 e) Saccharomyces cerevisiae (70%) f) K2C03/Me0H.

Figure 39 Biochemical preparation of the enantiomers of methyl 3-hydroxypentanoate.

Methyl 5-methyl-6-ox oh exanoate 4. 5-Carbamoyl-4-hydroxypentanoic acid... 

Lipase-catalyzed polymerizahon of oxyacid esters was reported. PPL catalyzed the polymerizahon of methyl 6-hydroxyhexanoate. ° The polymer with DP up to 100 was synthesized by polymerization in hexane at 69°C for more than 50 days. The PPL-catalyzed polymerization of methyl 5-hydroxypentanoate for 60 days produced the polymer with DP of 29. Solvent effects were... 

Optically active 3-hydroxybutanoic acid and its methyl ester were first prepared by McKenzie, Magnus-Levy, and Emil Fischer.3 The biopolymer PHB and mixed polymers containing (R)-3-hydroxybutanoate and (R)-3-hydroxypentanoate were also discovered long ago,4 5 and are now produced on an industrial scale. .7 As described here, depolymerization by transesterification [H+ or Ti(OR)4 catalysis], or by hydrolysis, produces8-9 the corresponding monomeric (R)-esters and (R)-acids 1. The 3-hydroxybutanoic acid can also be prepared by hydrolysis of the ester.2-10... 

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... 

Reduction of octyl 3-oxopentanoate with baker s yeast furnishes octyl (S)-3-hydroxypentanoate of 97% e.e. After transesterification to the corresponding methyl ester 18, it can be purified as its 3,5-dinitrobenzoate to give (S)-18 of 100% e.e. (21). 

Mori started with the early introduction of the chiral centre [298] in using (3-oxidation of pentanoic acid A by the yeast, Candida rugosa, IFO 0750 [299]. The obtained (R)-3-hydroxypentanoic acid B was transformed into C in a few conventional steps. The second building block was prepared from methyl 2-pentynoate D conjugate addition of lithium dimethyl cuprate yielded E, which was further converted into the frans-configured vinyl bromide F. Hydro-boration of C yielded G which upon Suzuki s palladium catalysed cross-coupling with F furnished 157 after treatment of the reaction product with hydrochloric acid followed by chromatographic purification. The synthesis of ent-157 used (S)-3-hydroxypentanoic acid. 

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)... 

Form Supplied in colorless oil commercially available. Analysis of Reagent Purity optical rotation NMR spectroscopy. Preparative Methods the preparation of (5, 5)-ethyl-DuPHOS is based on (3R,61 )-octane-3,6-diol as an enantiomerically pure starting compound. The latter is synthesized by a three-step procedure starting from methyl 3-oxopentanoate, which is transformed to methyl (l )-3-hydroxypentanoate (99% ee) by enantioselective hydrogenation with a Ru-(R)-BINAP catalyst, followed by hydrolysis to the hydroxy acid. The subsequent electrochemical Kolbe coupling reaction leads to (3R,6R)-octane-3,6-diol in a protocol that can be scaled up to multigram quantities (eq 1). ... 

Photosensitized oxygenation of the enolic forms of cyclohexane-1,2-diones in methanol gives 5-oxoalkanoic acids and methyl 5-carboxy-1-hydroxypentanoates with evolution of CO. The product distribution shows a marked temperature dependence which suggests that endoperoxides (16) and (17), present as unstable intermediates, are trapped by the solvent. a-Oxocarboxylic esters undergo direct photo-oxidation in polar and non-polar... 

PPL catalyzed the polymerization of methyl esters of 5-hydroxypentanoic and 6-hydroxyhexanoic acids.149 In the polymerization of the latter in hexane at 69 °C for more than 50 days, the polymer with DP up to 100 was formed. Relationships between solvent type and polymerization behaviors were systematically investigated hydrophobic solvents such as hydrocarbons and diisopropyl ether were suitable for the enzymatic production of high molecular weight polymer. Pseudomonas sp. lipase catalyzed the polymerization of ethyl esters of 3- and 4-hydroxybu-tyric acids, 5- and 6-hydroxyhexanoic acids, 5-hy-droxydodecanoic acid, and 15-hydroxypentadecanoic acid.157 Oxyacid vinyl esters were demonstrated as new monomers for polyester production under mild reaction conditions, yielding the corresponding polyesters with A/n of several thousands.276... 

Preparation of the hydroxypentanoic acid fragment was initiated by addition of the protected propargyl alcohol anion 109 to ethylene oxide. After silylation of the resulting alcohol, the ethoxy ethyl group was removed and the alkyne partially reduced to afford the (2)-alcohol 110 in 52% overall yield. Enantiospecific epoxidation of 110 under Sharpless s conditions and subsequent oxidation provided a 69% yield of diastereomerically pure epoxy acid 111. Treatment with trimethylaluminum gave almost exclusively the p-methyl acid, which was acylated to afford 112 (78%). 

The hydrosiiyiation of levulinates followed by acid solvolysis affords 4-methyl-y-butyrolactone with 80-84% e.e. through the silyl ether of 4-hydroxypentanoates, e.g.. 

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]... 

A Kolbe cross-coupling electrolysis reaction of 170 with propionic acid (MeOH, Et N, 35 °C) furnishes methyl (iS)-2-hydroxypentanoate which, after protection (TBS-Cl, imidazole, DMF) and saponification (KOH, EtOH), gives the TBS-protected a-hydroxy acid 171 in 58% overall yield [60].This hydroxy acid supplies the 0-1 to C-3 fragment in the convergent synthesis of the antibiotic myxovirescine (172). 

Propanoyl chloride Propionyl chloride (8) Propanoyl chloride (9) (79-03-8) 2, 6 -01 methyl phenyl (2SR.3SR)-2,4-diraethyl-3-hydroxypentanoate Pentanolc... 

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... 

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